diff --git a/app/controllers/redirect.php b/app/controllers/redirect.php
index 1c7b39568..6f1d01721 100644
--- a/app/controllers/redirect.php
+++ b/app/controllers/redirect.php
@@ -4,7 +4,9 @@
 use Opencast\Models\VideosShares;
 use Opencast\Models\LTI\LtiHelper;
 use Opencast\Models\REST\ApiEventsClient;
+use Opencast\Models\REST\RestClient;
 use Opencast\Errors\Error;
+use Opencast\Errors\MaintenanceError;
 
 class RedirectController extends Opencast\Controller
 {
@@ -231,10 +233,13 @@ private function getLtiLinkFor($lti, $endpoint)
     }
 
     /**
-     * Load preview image from opencast and show it
+     * Serves a video preview image for the given video token.
      *
-     * @param String $episode_id
+     * Checks user permissions, fetches the preview image from Opencast if available,
+     * or falls back to a default image. Sets the appropriate content type header and outputs the image.
      *
+     * @param string $token The video token.
+     * @throws \Exception If access is denied.
      * @return void
      */
     public function preview_action($token)
@@ -247,17 +252,36 @@ public function preview_action($token)
             throw new \Exception('Access denied!');
         }
 
-        // get preview image
-        $api_events = ApiEventsClient::getInstance($video->config_id);
+        $plugin_path = $GLOBALS['ABSOLUTE_PATH_STUDIP'] . $this->plugin->getPluginPath();
+        $default_image_relative_path = '/assets/images/default-preview.png';
+        $image_default_url = URLHelper::getURL($this->plugin->getPluginUrl() . $default_image_relative_path);
+        $image_mimetype = mime_content_type($plugin_path . $default_image_relative_path);
+        $image_content = null;
+        if ($video->preview) {
+            $rest_client = null;
+            try {
+                $rest_client = ApiEventsClient::getInstance($video->config_id);
+            } catch (\Throwable $th) {
+                if ($th instanceof MaintenanceError) {
+                    $rest_client = RestClient::createReadOnlyInstance($video->config_id);
+                }
+            }
+
+            if (!empty($rest_client)) {
+                $response = $rest_client->fileRequest($video->preview);
+                $image_content = $response['body'] ?? null;
+                $image_mimetype = $response['mimetype'] ?? $image_mimetype;
+            }
+        }
 
-        $image = $video->preview ?
-            : URLHelper::getURL($this->plugin->getPluginUrl() . '/assets/images/default-preview.png');
+        if (empty($image_content)) {
+            $image_content = file_get_contents($image_default_url);
+        }
 
-        $response = $api_events->fileRequest($image);
+        header('Content-Type: '. $image_mimetype);
 
-        header('Content-Type: '. $response['mimetype'][0]);
+        echo $image_content;
 
-        echo $response['body'];
         die;
     }
 }
diff --git a/assets/css/opencast.scss b/assets/css/opencast.scss
index 2d6282f94..4a8609e77 100644
--- a/assets/css/opencast.scss
+++ b/assets/css/opencast.scss
@@ -1477,4 +1477,18 @@ label.oc--file-upload {
     .oc--loading-indicator {
         left: 50%;
     }
-}
\ No newline at end of file
+}
+
+/* * * * * * * * * * * */
+/*     MESSAGE BOX     */
+/* * * * * * * * * * * */
+
+.messagebox {
+    .messagebox-html-container {
+        font-weight: 400 !important;
+        margin: 0px !important;
+        > p {
+            margin: 0px !important;
+        }
+    }
+}
diff --git a/cronjobs/opencast_clear_recycle_bin.php b/cronjobs/opencast_clear_recycle_bin.php
index cb1561d68..224e569ee 100644
--- a/cronjobs/opencast_clear_recycle_bin.php
+++ b/cronjobs/opencast_clear_recycle_bin.php
@@ -46,8 +46,8 @@ public function execute($last_result, $parameters = array())
         foreach ($videos_by_config as $config_id => $videos) {
             echo 'Working on config with id #' . $config_id . "\n";
 
-            // Checking the connection.
-            if (!$this->isOpencastReachable($config_id)) {
+            // Checking the connection and maintenance status.
+            if (!$this->isOpencastReachable($config_id) || $this->isOpencastUnderMaintenance($config_id)) {
                 continue;
             }
 
diff --git a/cronjobs/opencast_discover_videos.php b/cronjobs/opencast_discover_videos.php
index dc085ca19..64c745d33 100644
--- a/cronjobs/opencast_discover_videos.php
+++ b/cronjobs/opencast_discover_videos.php
@@ -51,7 +51,8 @@ public function execute($last_result, $parameters = array())
         foreach ($configs as $config) {
             echo 'Working on config with id #' . $config->id . "\n";
 
-            if (!$this->isOpencastReachable($config->id)) {
+            // Checking the connection and maintenance status.
+            if (!$this->isOpencastReachable($config->id) || $this->isOpencastUnderMaintenance($config->id)) {
                 continue;
             }
 
diff --git a/cronjobs/opencast_refresh_scheduling.php b/cronjobs/opencast_refresh_scheduling.php
index 2de1260c9..6aa51e94f 100644
--- a/cronjobs/opencast_refresh_scheduling.php
+++ b/cronjobs/opencast_refresh_scheduling.php
@@ -55,7 +55,8 @@ public function execute($last_result, $parameters = array())
 
             echo 'Working on config with id #' . $config_id . "\n";
 
-            if (!$this->isOpencastReachable($config_id)) {
+            // Checking the connection and maintenance status.
+            if (!$this->isOpencastReachable($config_id) || $this->isOpencastUnderMaintenance($config_id)) {
                 continue;
             }
 
diff --git a/cronjobs/opencast_sync_acls.php b/cronjobs/opencast_sync_acls.php
index c98db0b38..4c20bdad5 100644
--- a/cronjobs/opencast_sync_acls.php
+++ b/cronjobs/opencast_sync_acls.php
@@ -41,7 +41,8 @@ public function execute($last_result, $parameters = array())
         foreach ($configs as $config) {
             echo 'Working on config with id #' . $config->id . "\n";
 
-            if (!$this->isOpencastReachable($config->id)) {
+            // Checking the connection and maintenance status.
+            if (!$this->isOpencastReachable($config->id) || $this->isOpencastUnderMaintenance($config->id)) {
                 continue;
             }
 
diff --git a/cronjobs/opencast_sync_playlists.php b/cronjobs/opencast_sync_playlists.php
index 5c3a6c5b4..06da49f75 100644
--- a/cronjobs/opencast_sync_playlists.php
+++ b/cronjobs/opencast_sync_playlists.php
@@ -35,7 +35,8 @@ public function execute($last_result, $parameters = array())
         foreach ($configs as $config) {
             echo 'Working on config with id #' . $config->id . "\n";
 
-            if (!$this->isOpencastReachable($config->id)) {
+            // Checking the connection and maintenance status.
+            if (!$this->isOpencastReachable($config->id) || $this->isOpencastUnderMaintenance($config->id)) {
                 continue;
             }
 
diff --git a/lib/Errors/MaintenanceError.php b/lib/Errors/MaintenanceError.php
new file mode 100644
index 000000000..3918a7a1f
--- /dev/null
+++ b/lib/Errors/MaintenanceError.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Opencast\Errors;
+
+class MaintenanceError extends Error
+{
+    function __construct($message = null)
+    {
+        $message = $message ?? _('Opencast befindet sich derzeit in Wartung');
+        parent::__construct($message, 503);
+    }
+}
diff --git a/lib/Helpers/CronjobUtils/OpencastConnectionCheckerTrait.php b/lib/Helpers/CronjobUtils/OpencastConnectionCheckerTrait.php
index 102db223a..124e5c85d 100644
--- a/lib/Helpers/CronjobUtils/OpencastConnectionCheckerTrait.php
+++ b/lib/Helpers/CronjobUtils/OpencastConnectionCheckerTrait.php
@@ -3,6 +3,7 @@
 namespace Opencast\Helpers\CronjobUtils;
 
 use Opencast\Models\REST\Config as OCConfig;
+use Opencast\Models\Config as ConfigModel;
 
 trait OpencastConnectionCheckerTrait
 {
@@ -11,6 +12,11 @@ trait OpencastConnectionCheckerTrait
      */
     private $not_reachable_message = 'Opencast is currently unreachable. Process postponed.';
 
+    /**
+     * @var string $not_reachable_message Message to display when Opencast is not reachable.
+     */
+    private $maintenance_message = 'Opencast is currently under maintenance. Process postponed.';
+
     /**
      * Checks if the Opencast instance is reachable for the given configuration ID.
      *
@@ -35,4 +41,26 @@ protected function isOpencastReachable(int $config_id, bool $check_engage_node =
         }
         return $is_opencast_reachable;
     }
+
+    /**
+     * Checks if the Opencast instance is under maintenance for the given configuration ID.
+     *
+     * This method checks if the Opencast instance is currently under maintenance.
+     * If it is, it prints a message and returns true. Otherwise, it returns false.
+     *
+     * @param int $config_id The ID of the Opencast configuration to check.
+     * @return bool True if Opencast is under maintenance, false otherwise.
+     */
+    protected function isOpencastUnderMaintenance(int $config_id)
+    {
+        $oc_config = ConfigModel::findOneBySql("id = ?", [$config_id]);
+        if ($oc_config) {
+            list($maintenance_active, $read_only) = $oc_config->isUnderMaintenance();
+            if ($maintenance_active) {
+                echo $this->maintenance_message . "\n";
+                return true;
+            }
+        }
+        return false;
+    }
 }
diff --git a/lib/Models/Config.php b/lib/Models/Config.php
index d6b1fc7fe..4e4d783bd 100644
--- a/lib/Models/Config.php
+++ b/lib/Models/Config.php
@@ -16,6 +16,10 @@ class Config extends \SimpleOrMap
         'lti_consumerkey', 'lti_consumersecret', 'debug', 'ssl_ignore_cert_errors', 'episode_id_role_access'
     ];
 
+    const MAINTENANCE_MODE_OFF = 'off';
+    const MAINTENANCE_MODE_ON = 'on';
+    const MAINTENANCE_MODE_READONLY = 'read-only';
+
     protected static function configure($config = [])
     {
         $config['db_table'] = 'oc_config';
@@ -28,27 +32,62 @@ protected static function configure($config = [])
     }
 
     /**
-     * function getConfigForService  - retries configutation for a given REST-Service-Client
-     *
-     * @param string $service_type - client label
+     * Returns the merged configuration and endpoint data for a given service type and config ID.
      *
-     * @return array configuration for corresponding client
+     * Retrieves the Opencast configuration and endpoint for the specified service type and configuration ID,
+     * taking maintenance mode into account. Returns false if configuration or endpoint is missing,
+     * or null if access is not allowed due to maintenance restrictions.
      *
+     * @param string $service_type The type of Opencast service (e.g., 'ingest', 'search').
+     * @param int $config_id The configuration ID (default: 1).
+     * @return array|false|null Merged configuration and endpoint data, false if not found, or null if not accessible.
+     * @throws \Exception In case something goes wrong!
      */
     public static function getConfigForService($service_type, $config_id = 1)
     {
         if (isset($service_type)) {
-            $config = Endpoints::findOneBySQL(
+            $result = [];
+
+            $oc_config = self::find($config_id);
+            $endpoint_config = Endpoints::findOneBySQL(
                 'service_type = ? AND config_id = ?' ,
                 [$service_type, $config_id]
             );
 
-            if ($config) {
-                return $config->toArray() + self::find($config_id)->toArray();
-            } else {
+            if (empty($oc_config) || empty($endpoint_config)) {
                 return false;
             }
 
+            list($maintenance_on, $maintenance_readonly) = $oc_config->isUnderMaintenance();
+
+            $can_access = !$maintenance_on ||
+                ($maintenance_readonly && in_array($service_type, RESTConfig::ENGAGE_NODE_SERVICE_TYPES));
+
+            if (!$can_access) {
+                return null;
+            }
+
+            $oc_config_array = $oc_config->toArray();
+            $endpoint_config_array = $endpoint_config->toArray();
+
+            // Here we need to replace the service_url with the maintenance_engage_url_fallback (1. priority) if provided in config
+            // or the endpoint service_url (2. priority)
+            if ($maintenance_readonly) {
+                $replacing_server_url = $oc_config_array['maintenance_engage_url_fallback'];
+                if (empty($replacing_server_url)) {
+                    $replacing_server_url = $endpoint_config_array['service_url'];
+                }
+                $replacing_server_url_parsed = parse_url($replacing_server_url);
+
+                $replacing_server_url_clean = $replacing_server_url_parsed['scheme'] . '://'. $replacing_server_url_parsed['host']
+                    . (isset($replacing_server_url_parsed['port']) ? ':' . $replacing_server_url_parsed['port'] : '');
+
+                $oc_config_array['service_url'] = $replacing_server_url_clean;
+            }
+
+            $result = $endpoint_config_array + $oc_config_array;
+
+            return $result;
         } else {
             throw new \Exception(_("Es wurde kein Servicetyp angegeben."));
         }
@@ -163,6 +202,18 @@ public function updateSettings($json)
      */
     public function updateEndpoints()
     {
+
+        list($maintenance_on, $maintenance_readonly) = $this->isUnderMaintenance();
+
+        // Prevent updating endpoints if the server is under maintenance.
+        if ($maintenance_on) {
+            $message = [
+                'type' => 'warning',
+                'text' => _('Diese Opencast-Instanz ist derzeit im Wartungsmodus, daher können Endpunkte nicht aktualisiert werden.')
+            ];
+            return $message;
+        }
+
         $service_url =  parse_url($this->service_url);
 
         // check the selected url for validity
@@ -257,7 +308,7 @@ public function updateEndpoints()
                     }
 
                     // create new entries for workflow_config table
-                    WorkflowConfig::createAndUpdateByConfigId($this->id, $workflows);
+                    WorkflowConfig::createAndUpdateByConfigId($this->id);
 
                     $success_message[] = sprintf(
                         _('Die Opencast-Installation "%s" wurde erfolgreich konfiguriert.'),
@@ -282,4 +333,22 @@ public function updateEndpoints()
 
         return $message;
     }
+
+    /**
+     * Checks if the Opencast instance is in maintenance mode.
+     *
+     * @param bool $with_keys Whether to return an associative array with keys ('active', 'read_only').
+     * @return array [maintenance_on, maintenance_readonly] or ['active' => bool, 'read_only' => bool] if $with_keys is true.
+     */
+    public function isUnderMaintenance($with_keys = false)
+    {
+        $maintenance_on = ($this->maintenance_mode === self::MAINTENANCE_MODE_ON
+            || $this->maintenance_mode === self::MAINTENANCE_MODE_READONLY);
+
+        $res = [
+            'active' => $maintenance_on,
+            'read_only' => $this->maintenance_mode === self::MAINTENANCE_MODE_READONLY
+        ];
+        return $with_keys ? $res : array_values($res);
+    }
 }
diff --git a/lib/Models/LTI/LtiHelper.php b/lib/Models/LTI/LtiHelper.php
index 1add5d01e..d8a8e8a9a 100644
--- a/lib/Models/LTI/LtiHelper.php
+++ b/lib/Models/LTI/LtiHelper.php
@@ -5,6 +5,7 @@
 use Opencast\Models\Config;
 use Opencast\Models\Endpoints;
 use Opencast\Providers\Perm;
+use Opencast\Models\REST\Config as RESTConfig;
 
 /**
  * LTI Helper class to create launch data
@@ -22,15 +23,27 @@ class LtiHelper
     public static function getLtiLinks($config_id)
     {
         $links = [];
-        $endpoints = Endpoints::findByConfig_id($config_id);
         $config    = Config::find($config_id);
 
+        list($maintenance_active, $read_only) = $config->isUnderMaintenance();
+
+        if ($maintenance_active && !$read_only) {
+            return [];
+        }
+
+        $endpoints = Endpoints::findByConfig_id($config_id);
+
         foreach ($endpoints as $endpoint) {
             // skip 'services' endpoints
             if ($endpoint->service_type == 'services') {
                 continue;
             }
 
+            // In read-only maintenance mode, we only allow engage node services!
+            if ($read_only && !in_array($endpoint->service_type, RESTConfig::ENGAGE_NODE_SERVICE_TYPES)) {
+                continue;
+            }
+
             $url = parse_url($endpoint['service_url']);
 
             $lti_url = $url['scheme'] . '://'. $url['host']
diff --git a/lib/Models/REST/ApiEventsClient.php b/lib/Models/REST/ApiEventsClient.php
index 4bf95f5d6..61cd27480 100644
--- a/lib/Models/REST/ApiEventsClient.php
+++ b/lib/Models/REST/ApiEventsClient.php
@@ -1,23 +1,19 @@
 <?php
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
 use Opencast\Models\Helpers;
 use Opencast\Models\Pager;
 
 class ApiEventsClient extends RestClient
 {
     public static $me;
-    public        $serviceName = 'ApiEvents';
 
     public function __construct($config_id = 1)
     {
-        if ($config = Config::getConfigForService('apievents', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceName = 'ApiEvents';
+        $this->serviceType = 'apievents';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
diff --git a/lib/Models/REST/ApiPlaylistsClient.php b/lib/Models/REST/ApiPlaylistsClient.php
index c72d62672..c2552aa98 100644
--- a/lib/Models/REST/ApiPlaylistsClient.php
+++ b/lib/Models/REST/ApiPlaylistsClient.php
@@ -1,21 +1,16 @@
 <?php
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
-
 class ApiPlaylistsClient extends RestClient
 {
     public static $me;
-    public        $serviceName = 'ApiPlaylists';
 
     public function __construct($config_id = 1)
     {
-        if ($config = Config::getConfigForService('apiplaylists', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceName = 'ApiPlaylists';
+        $this->serviceType = 'apiplaylists';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
diff --git a/lib/Models/REST/ApiWorkflowsClient.php b/lib/Models/REST/ApiWorkflowsClient.php
index 2bc3668f4..52c7cb43a 100644
--- a/lib/Models/REST/ApiWorkflowsClient.php
+++ b/lib/Models/REST/ApiWorkflowsClient.php
@@ -1,21 +1,16 @@
 <?php
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
-
 class ApiWorkflowsClient extends RestClient
 {
     public static $me;
-    public $serviceName = "ApiWorkflows";
 
     function __construct($config_id = 1)
     {
-        if ($config = Config::getConfigForService('apiworkflows', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceName = 'ApiWorkflows';
+        $this->serviceType = 'apiworkflows';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
diff --git a/lib/Models/REST/CaptureAgentAdminClient.php b/lib/Models/REST/CaptureAgentAdminClient.php
index 2a9c96188..f0e48c151 100644
--- a/lib/Models/REST/CaptureAgentAdminClient.php
+++ b/lib/Models/REST/CaptureAgentAdminClient.php
@@ -1,8 +1,6 @@
 <?php
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
-
 class CaptureAgentAdminClient extends RestClient
 {
     public static $me;
@@ -10,24 +8,20 @@ class CaptureAgentAdminClient extends RestClient
     public function __construct($config_id = 1)
     {
         $this->serviceName = 'CaptureAgentAdminClient';
-
-        if ($config = Config::getConfigForService('capture-admin', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceType = 'capture-admin';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
      * Retrieves capture agents of connected opencast
-     * 
+     *
      * @return array|boolean array of capture agent list or false if unable to get.
      */
     public function getCaptureAgents()
     {
         $response = $this->opencastApi->captureAdmin->getAgents();
-        
+
         if ($response['code'] == 200) {
             return $this->sanitizeAgents($response['body']);
         }
@@ -36,15 +30,15 @@ public function getCaptureAgents()
 
     /**
      * Retrieves the capabilities of a given capture agent
-     * 
+     *
      * @param string $agent_name name of capture agent
-     * 
+     *
      * @return object|boolean capability object, or false if unable to get
      */
     public function getCaptureAgentCapabilities($agent_name)
     {
         $response = $this->opencastApi->captureAdmin->getAgentCapabilities($agent_name);
-        
+
         if ($response['code'] == 200) {
             $capability = $response['body'];
             $x = 'properties-response';
@@ -56,9 +50,9 @@ public function getCaptureAgentCapabilities($agent_name)
 
     /**
      * Sanitizes the list of capture agents.
-     * 
+     *
      * @param object $agents the list of agents
-     * 
+     *
      * @return array agents array list
      */
     private function sanitizeAgents($agents)
@@ -66,7 +60,7 @@ private function sanitizeAgents($agents)
         if (!isset($agents->agents->agent) || empty($agents->agents->agent)) {
             return [];
         }
-        
+
         if (is_array($agents->agents->agent)) {
             return $agents->agents->agent;
         }
diff --git a/lib/Models/REST/Config.php b/lib/Models/REST/Config.php
index b058c94aa..71b3a6004 100644
--- a/lib/Models/REST/Config.php
+++ b/lib/Models/REST/Config.php
@@ -22,6 +22,11 @@ class Config
         'org.opencastproject.workflow'                     => 'workflow',
     ];
 
+    const ENGAGE_NODE_SERVICE_TYPES = [
+        'play',
+        'search',
+    ];
+
     /**
      * Get the connected opencast instance version
      *
diff --git a/lib/Models/REST/IngestClient.php b/lib/Models/REST/IngestClient.php
index 841c28172..7a45e4b68 100644
--- a/lib/Models/REST/IngestClient.php
+++ b/lib/Models/REST/IngestClient.php
@@ -1,8 +1,6 @@
 <?php
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
-
 class IngestClient extends RestClient
 {
     public static $me;
@@ -10,13 +8,9 @@ class IngestClient extends RestClient
     public function __construct($config_id = 1)
     {
         $this->serviceName = 'IngestClient';
-
-        if ($config = Config::getConfigForService('ingest', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceType = 'ingest';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
diff --git a/lib/Models/REST/RestClient.php b/lib/Models/REST/RestClient.php
index c6e7686f4..3f919d435 100644
--- a/lib/Models/REST/RestClient.php
+++ b/lib/Models/REST/RestClient.php
@@ -5,6 +5,7 @@
 namespace Opencast\Models\REST;
 
 use Opencast\Models\Config;
+use Opencast\Errors\MaintenanceError;
 use Opencast\Errors\RESTError;
 use OpencastApi\Opencast;
 use OpencastApi\Rest\OcRestClient;
@@ -27,6 +28,7 @@ class RestClient
     public $ocRestClient;
 
     public $serviceName = 'ParentRestClientClass';
+    public $serviceType;
 
     /**
      * Get singleton instance of client
@@ -113,8 +115,44 @@ public function fileRequest($file_url)
         }
 
         $result['body']     = $body;
-        $result['mimetype'] = $response->getHeader('Content-Type');
+        $result['mimetype'] = $response->getHeaderLine('Content-Type');
 
         return $result;
     }
+
+    /**
+     * Retrieves the configuration for the client based on service type and config ID.
+     *
+     * Throws a MaintenanceError if the config is null, or a generic Exception if the config is invalid.
+     *
+     * @param int $config_id The configuration ID.
+     * @return array The configuration array.
+     * @throws MaintenanceError|\Exception
+     */
+    protected function getConfigForClient($config_id)
+    {
+        $config = Config::getConfigForService($this->serviceType, $config_id);
+        if (is_null($config)) {
+            throw new MaintenanceError();
+        } else if ($config === false) {
+            throw new \Exception ($this->serviceName . ': '
+                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
+        }
+        return $config;
+    }
+
+    /**
+     * Creates a read-only RestClient instance for the given config ID.
+     *
+     * Uses the 'search' service type to fetch configuration and returns a new instance,
+     * or null if configuration is missing.
+     *
+     * @param int $config_id The configuration ID.
+     * @return static|null The read-only RestClient instance or null if not available.
+     */
+    public static function createReadOnlyInstance($config_id)
+    {
+        $read_only_config = Config::getConfigForService('search', $config_id);
+        return !empty($read_only_config) ? new static($read_only_config) : null;
+    }
 }
diff --git a/lib/Models/REST/SchedulerClient.php b/lib/Models/REST/SchedulerClient.php
index 4fd696f52..da6769809 100644
--- a/lib/Models/REST/SchedulerClient.php
+++ b/lib/Models/REST/SchedulerClient.php
@@ -2,29 +2,25 @@
 
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
-
 class SchedulerClient extends RestClient
 {
+
+
     public static $me;
 
     public function __construct($config_id = 1)
     {
         $this->serviceName = 'SchedulerClient';
-
-        if ($config = Config::getConfigForService('recordings', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceType = 'recordings';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
      * Deletes an event
-     * 
+     *
      * @param string $event_id the event id
-     * 
+     *
      * @return boolean success or not
      */
     public function deleteEvent($event_id)
@@ -39,7 +35,7 @@ public function deleteEvent($event_id)
 
     /**
      * Updates an event
-     * 
+     *
      * @param string $event_id the event id
      * @param int $start start of the event
      * @param int $end end of the event
@@ -48,7 +44,7 @@ public function deleteEvent($event_id)
      * @param string $mediaPackage mediapackage
      * @param string|array $wfproperties workflow properties
      * @param string|array $agentparameters agent params
-     * 
+     *
      * @return boolean success or not
      */
     public function updateEvent($event_id, $start = 0, $end = 0, $agent = '', $users = '', $mediaPackage = '', $wfproperties = '', $agentparameters = '')
diff --git a/lib/Models/REST/SeriesClient.php b/lib/Models/REST/SeriesClient.php
index e9cd132ab..ce610ebe2 100644
--- a/lib/Models/REST/SeriesClient.php
+++ b/lib/Models/REST/SeriesClient.php
@@ -2,7 +2,6 @@
 
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
 use Opencast\Models\Helpers;
 
 class SeriesClient extends RestClient
@@ -12,13 +11,9 @@ class SeriesClient extends RestClient
     public function __construct($config_id = 1)
     {
         $this->serviceName = 'Series';
-
-        if ($config = Config::getConfigForService('series', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceType = 'series';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
diff --git a/lib/Models/REST/ServicesClient.php b/lib/Models/REST/ServicesClient.php
index cc8818c63..90a705913 100644
--- a/lib/Models/REST/ServicesClient.php
+++ b/lib/Models/REST/ServicesClient.php
@@ -2,8 +2,6 @@
 
 namespace Opencast\Models\REST;
 
-use Opencast\Models\Config;
-
 class ServicesClient extends RestClient
 {
     public static $me;
@@ -11,15 +9,9 @@ class ServicesClient extends RestClient
     public function __construct($config_id = 1, $custom_config = null)
     {
         $this->serviceName = 'ServicesClient';
-
-        if ($custom_config) {
-            parent::__construct($custom_config);
-        } else if ($config = Config::getConfigForService('services', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceType = 'services';
+        $config = $custom_config ?? $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
     /**
diff --git a/lib/Models/REST/WorkflowClient.php b/lib/Models/REST/WorkflowClient.php
index 09c917a72..deb9aeec9 100644
--- a/lib/Models/REST/WorkflowClient.php
+++ b/lib/Models/REST/WorkflowClient.php
@@ -1,7 +1,6 @@
 <?php
 
 namespace Opencast\Models\REST;
-use Opencast\Models\Config;
 
 class WorkflowClient extends RestClient
 {
@@ -10,13 +9,9 @@ class WorkflowClient extends RestClient
     public function __construct($config_id = 1)
     {
         $this->serviceName = 'WorkflowClient';
-
-        if ($config = Config::getConfigForService('workflow', $config_id)) {
-            parent::__construct($config);
-        } else {
-            throw new \Exception ($this->serviceName . ': '
-                . _('Die Opencast-Konfiguration wurde nicht korrekt angegeben'));
-        }
+        $this->serviceType = 'workflow';
+        $config = $this->getConfigForClient($config_id);
+        parent::__construct($config);
     }
 
 
@@ -38,9 +33,9 @@ public function getDefinitions()
         return false;
     }
 
-     ####################
-     # HELPER FUNCTIONS #
-     ####################
+    ####################
+    # HELPER FUNCTIONS #
+    ####################
 
     /**
      * Returns a revised collection of all tagged Workflow definitions
diff --git a/lib/Models/Videos.php b/lib/Models/Videos.php
index ec553bcfa..1114c4cac 100644
--- a/lib/Models/Videos.php
+++ b/lib/Models/Videos.php
@@ -437,7 +437,9 @@ protected static function getFilteredVideos($query, $filters)
         }
 
         // Only show videos with active server
-        $sql .= ' INNER JOIN oc_config ON (oc_config.id = oc_video.config_id AND oc_config.active = 1)';
+        $sql .= ' INNER JOIN oc_config ON
+            (oc_config.id = oc_video.config_id AND oc_config.active = 1
+                AND oc_config.maintenance_mode <> "' . \Opencast\Models\Config::MAINTENANCE_MODE_ON . '")';
 
         $where .= " AND trashed = " . $filters->getTrashed();
         $where .= " AND oc_video.token IS NOT NULL";
diff --git a/lib/Routes/Config/SimpleConfigList.php b/lib/Routes/Config/SimpleConfigList.php
index 34a3414f1..3cf392593 100644
--- a/lib/Routes/Config/SimpleConfigList.php
+++ b/lib/Routes/Config/SimpleConfigList.php
@@ -43,7 +43,9 @@ public function __invoke(Request $request, Response $response, $args)
                 'apiplaylists'  => $this->getServiceUrl('apiplaylists', $conf->id),
                 'apiworkflows'  => $this->getServiceUrl('apiworkflows', $conf->id),
                 'studio'        => $conf->service_url . '/studio/index.html',
-                'lti_num'       => sizeof(LtiHelper::getLtiLinks($conf->id))              // used to iterate over all Opencast nodes
+                'lti_num'       => sizeof(LtiHelper::getLtiLinks($conf->id)), // used to iterate over all Opencast nodes,
+                'maintenance_mode' => $conf->isUnderMaintenance(true),
+                'maintenance_text' => $conf->maintenance_text ?? '',
             ];
         }
 
diff --git a/lib/Routes/Playlist/PlaylistAddVideos.php b/lib/Routes/Playlist/PlaylistAddVideos.php
index a68529449..065acd7f5 100644
--- a/lib/Routes/Playlist/PlaylistAddVideos.php
+++ b/lib/Routes/Playlist/PlaylistAddVideos.php
@@ -40,6 +40,10 @@ public function __invoke(Request $request, Response $response, $args)
         }
 
         if (!PlaylistMigration::isConverted()) {
+            // In favor of checking maintenance mode in API client level,
+            // we should check the ACL of each video before adding it to the playlist.
+            Videos::checkEventACL(null, null, $video);
+
             foreach ($videos as $video) {
                 $plvideo = new PlaylistVideos;
                 $plvideo->setData([
@@ -55,8 +59,6 @@ public function __invoke(Request $request, Response $response, $args)
 
             $playlist->videos->store();
 
-            Videos::checkEventACL(null, null, $video);
-
             return $response->withStatus(204);
         }
 
diff --git a/lib/Routes/Playlist/PlaylistRemoveVideos.php b/lib/Routes/Playlist/PlaylistRemoveVideos.php
index 64800e378..d8544a97a 100644
--- a/lib/Routes/Playlist/PlaylistRemoveVideos.php
+++ b/lib/Routes/Playlist/PlaylistRemoveVideos.php
@@ -39,6 +39,9 @@ public function __invoke(Request $request, Response $response, $args)
 
         if (!PlaylistMigration::isConverted()) {
             foreach ($videos as $video) {
+                // In favor of checking maintenance mode in API client level,
+                // we should check the ACL of each video before removing it from the playlist.
+                Videos::checkEventACL(null, null, $video);
 
                 $plvideo = PlaylistVideos::findOneBySQL(
                     'playlist_id = :playlist_id AND video_id = :video_id',
@@ -50,8 +53,6 @@ public function __invoke(Request $request, Response $response, $args)
                 $plvideo->delete();
             }
 
-            Videos::checkEventACL(null, null, $video);
-
             return $response->withStatus(204);
         }
 
diff --git a/lib/Routes/User/UserSeriesShow.php b/lib/Routes/User/UserSeriesShow.php
index f6aa4347b..56a834aa7 100644
--- a/lib/Routes/User/UserSeriesShow.php
+++ b/lib/Routes/User/UserSeriesShow.php
@@ -18,17 +18,20 @@ public function __invoke(Request $request, Response $response, $args)
     {
         global $user;
 
-        $series = UserSeries::getSeries($user->id);
+        try {
+            $series = UserSeries::getSeries($user->id);
 
-        if (empty($series)) {
-            $series = UserSeries::createSeries($user->id);
-        }
-        else {
-            $series = $series[0];
+            if (empty($series)) {
+                $series = UserSeries::createSeries($user->id);
+            } else {
+                $series = $series[0];
+            }
+        } catch (\Throwable $th) {
+            // We do nothing here as to return a null series to display warning.
         }
 
         return $this->createResponse([
-            'series_id' => $series['series_id']
+            'series_id' => $series['series_id'] ?? null
         ], $response);
     }
-}
\ No newline at end of file
+}
diff --git a/migrations/113_add_oc_config_maintenance_columns.php b/migrations/113_add_oc_config_maintenance_columns.php
new file mode 100644
index 000000000..5d5033b26
--- /dev/null
+++ b/migrations/113_add_oc_config_maintenance_columns.php
@@ -0,0 +1,35 @@
+<?php
+
+class AddOcConfigMaintenanceColumns extends Migration
+{
+    public function description()
+    {
+        return 'Add Maintenance mode related columns to oc_config table';
+    }
+
+    public function up()
+    {
+        $db = DBManager::get();
+
+        $db->exec("ALTER TABLE `oc_config`
+            ADD COLUMN `maintenance_mode` ENUM('off', 'on', 'read-only') CHARACTER SET latin1 COLLATE latin1_bin NOT NULL DEFAULT 'off',
+            ADD COLUMN `maintenance_engage_url_fallback` varchar(255) NOT NULL,
+            ADD COLUMN `maintenance_text` TEXT DEFAULT NULL
+        ");
+
+        SimpleOrMap::expireTableScheme();
+    }
+
+    public function down()
+    {
+        $db = DBManager::get();
+
+        $db->exec('ALTER TABLE `oc_config`
+            DROP COLUMN `maintenance_mode`,
+            DROP COLUMN `maintenance_engage_url_fallback`,
+            DROP COLUMN `maintenance_text`'
+        );
+
+        SimpleOrMap::expireTableScheme();
+    }
+}
diff --git a/vueapp/App.vue b/vueapp/App.vue
index ef60c6a83..b8f6dbf85 100644
--- a/vueapp/App.vue
+++ b/vueapp/App.vue
@@ -23,6 +23,12 @@ export default {
 
     computed: {
         ...mapGetters(['site'])
+    },
+
+    // We moved the loading of simple config into the top level,
+    // in order to reduce unwanted calls in various places!
+    async beforeMount() {
+        await this.$store.dispatch('simpleConfigListRead');
     }
 };
 </script>
diff --git a/vueapp/app.js b/vueapp/app.js
index c63990663..5d5d2cdc4 100644
--- a/vueapp/app.js
+++ b/vueapp/app.js
@@ -50,7 +50,7 @@ window.addEventListener("DOMContentLoaded", function() {
                 return Promise.reject(error);
             }
 
-            if (error.response.data !== undefined) {
+            if (error?.response?.data !== undefined) {
                 store.dispatch('addMessage', error.response);
             }
 
diff --git a/vueapp/components/Config/EditServer.vue b/vueapp/components/Config/EditServer.vue
index 6e844fb38..38db27e92 100644
--- a/vueapp/components/Config/EditServer.vue
+++ b/vueapp/components/Config/EditServer.vue
@@ -26,6 +26,8 @@
                             @updateValue="updateValue" />
                     </fieldset>
 
+                    <MaintenanceOptions :currentConfig="currentConfig" :disabled="currentId === 'new'" />
+
                     <WorkflowOptions :disabled="currentId === 'new'" ref="workflow-form"/>
 
                     <UploadOptions :configId="currentId" :disabled="currentId === 'new'"/>
@@ -58,6 +60,7 @@ import MessageList from "@/components/MessageList";
 import ConfigOption from "@/components/Config/ConfigOption";
 import WorkflowOptions from "@/components/Config/WorkflowOptions";
 import UploadOptions from "@/components/Config/UploadOptions";
+import MaintenanceOptions from "@/components/Config/MaintenanceOptions";
 
 import axios from "@/common/axios.service";
 
@@ -72,6 +75,7 @@ export default {
         MessageList,
         WorkflowOptions,
         UploadOptions,
+        MaintenanceOptions
     },
 
     props: {
@@ -256,7 +260,7 @@ export default {
             }
         },
 
-        checkConfigResponse(data) {
+        async checkConfigResponse(data) {
             if (data.message !== undefined) {
                 if (data.message.type === 'error') {
                     this.$store.dispatch('addMessage', {
@@ -282,7 +286,7 @@ export default {
                         });
 
                         this.currentConfig = data.config;
-                        this.$store.dispatch('simpleConfigListRead');
+                        await this.$store.dispatch('simpleConfigListRead');
 
                         let view = this;
                         // We need to wait for a short time so the component is actually visible
@@ -298,6 +302,13 @@ export default {
                         this.$emit('close');
                     }
 
+                    return;
+                } else if (data.message.type === 'warning') {
+                    this.$store.dispatch('addMessage', {
+                        type: data.message.type,
+                        text: data.message.text,
+                        dialog: true
+                    });
                     return;
                 }
             }
@@ -318,10 +329,20 @@ export default {
 
             const regex = /^\d+\.\d+(?:\.\d+)?(?:[-.][a-zA-Z0-9]+)*$/;
             return regex.test(version);
+        },
+
+        printMaintenanceInfo() {
+            if (this.currentConfig?.maintenance_mode && this.currentConfig.maintenance_mode !== 'off') {
+                this.$store.dispatch('addMessage', {
+                    type: 'warning',
+                    text: this.$gettext('Der Server ist im Wartungsmodus.'),
+                    dialog: true
+                });
+            }
         }
     },
 
-    mounted() {
+    beforeMount() {
         if (this.currentId !== 'new') {
             if (!this.config) {
                 this.$store.dispatch('configRead', this.currentId)
@@ -332,7 +353,16 @@ export default {
                 this.currentConfig = this.config;
             }
         }
+    },
 
+    mounted() {
+        this.printMaintenanceInfo();
+    },
+
+    watch: {
+        currentConfig() {
+            this.printMaintenanceInfo();
+        }
     }
 };
 </script>
diff --git a/vueapp/components/Config/MaintenanceOptions.vue b/vueapp/components/Config/MaintenanceOptions.vue
new file mode 100644
index 000000000..fbb380aa3
--- /dev/null
+++ b/vueapp/components/Config/MaintenanceOptions.vue
@@ -0,0 +1,104 @@
+<template>
+    <div class="oc--admin--section">
+        <fieldset class="collapsable" v-if="!disabled">
+            <legend>
+                {{ $gettext('Server-Wartung') }}
+            </legend>
+
+            <span>
+                <div>
+                    <span>
+                        {{ $gettext('Wartungsmodus') }}
+                    </span>
+                </div>
+
+                <section class="hgroup size-m">
+                    <label>
+                        <input type="radio" value="off"
+                            name="maintenance_mode"
+                            :checked="currentConfig.maintenance_mode == 'off'"
+                            v-model="currentConfig.maintenance_mode"
+                            :disabled="disabled"
+                        >
+                        {{ $gettext('Aus') }}
+                    </label>
+                    <label>
+                        <input type="radio" value="on"
+                            name="maintenance_mode"
+                            :checked="currentConfig.maintenance_mode == 'on'"
+                            v-model="currentConfig.maintenance_mode"
+                            :disabled="disabled"
+                        >
+                        {{ $gettext('Ein') }}
+                    </label>
+                    <label>
+                        <input type="radio" value="read-only"
+                            name="maintenance_mode"
+                            :checked="currentConfig.maintenance_mode == 'read-only'"
+                            v-model="currentConfig.maintenance_mode"
+                            :disabled="disabled"
+                        >
+                        {{ $gettext('Nur Lesen') }}
+                    </label>
+                </section>
+            </span>
+
+            <label >
+                <span>
+                    {{ $gettext('Engage-Node ersatz URL') }}
+                </span>
+                <input type="text"
+                    v-model="currentConfig.maintenance_engage_url_fallback"
+                    placeholder="https://presentation.opencast.url"
+                    :disabled="disabled"
+                >
+            </label>
+
+            <label v-if="!disabled">
+                <span>
+                    {{ $gettext('Wartungstext') }}
+                </span>
+
+                <I18NText :text="currentConfig.maintenance_text ?? ''"
+                    :languages="config_list.languages"
+                    @updateValue="setTextValue"
+                />
+            </label>
+
+        </fieldset>
+    </div>
+</template>
+
+<script>
+import { mapGetters } from "vuex";
+import I18NText from "@/components/Config/I18NText";
+
+export default {
+    name: "MaintenanceOptions",
+
+    components: {
+        I18NText
+    },
+
+    props: {
+        currentConfig: {
+            type: Object,
+            required: true,
+        },
+        disabled: {
+            type: Boolean,
+            default: false
+        }
+    },
+
+    computed: {
+        ...mapGetters(['config_list']),
+    },
+
+    methods: {
+        setTextValue(newValue) {
+            this.currentConfig.maintenance_text = newValue;
+        }
+    },
+}
+</script>
diff --git a/vueapp/components/Config/ServerCard.vue b/vueapp/components/Config/ServerCard.vue
index 8a07694b5..3aa4e38d6 100644
--- a/vueapp/components/Config/ServerCard.vue
+++ b/vueapp/components/Config/ServerCard.vue
@@ -5,7 +5,7 @@
             <span v-if="!isAddCard" class="oc--admin--server-id">
                 <studip-icon
                     v-if="config.active"
-                    @click="toogleServer(false)"
+                    @click="toggleServer(false)"
                     shape="checkbox-checked"
                     role="clickable"
                     :size="32"
@@ -13,19 +13,27 @@
                 />
                 <studip-icon
                     v-else
-                    @click="toogleServer(true)"
+                    @click="toggleServer(true)"
                     shape="checkbox-unchecked"
                     role="clickable"
                     :size="32"
                     style="cursor: pointer"/>
             </span>
             <span class="oc--admin--server-icons">
-                <div data-tooltip class="tooltip" v-if="!isAddCard && checkFailed">
-                    <span class="tooltip-content" style="display: none">
-                        {{ $gettext('Verbindungstest fehlgeschlagen.') }}
-                    </span>
-                    <studip-icon shape="exclaim-circle" role="status-red" :size="32"/>
-                </div>
+                <template v-if="!isAddCard">
+                    <div data-tooltip class="tooltip" v-if="checkFailed">
+                        <span class="tooltip-content" style="display: none">
+                            {{ $gettext('Verbindungstest fehlgeschlagen.') }}
+                        </span>
+                        <studip-icon shape="exclaim-circle" role="status-red" :size="32"/>
+                    </div>
+                    <div data-tooltip class="tooltip" v-if="underMaintenance">
+                        <span class="tooltip-content" style="display: none">
+                            {{ $gettext('Wartungsmodus aktiv.') }}
+                        </span>
+                        <studip-icon shape="exclaim-circle" role="status-yellow" :size="32"/>
+                    </div>
+                </template>
             </span>
             <span v-if="isAddCard" class="oc--admin--server-id">
                 +
@@ -118,11 +126,19 @@ export default {
 
             const regex = /^\d+\.\d+(?:\.\d+)?(?:[-.][a-zA-Z0-9]+)*$/;
             return regex.test(version);
+        },
+
+        underMaintenance() {
+            if (this.isAddCard || !this.config?.maintenance_mode) {
+                return false;
+            }
+
+            return !this.isShow && this.config?.maintenance_mode !== 'off';
         }
     },
 
     methods: {
-        toogleServer(active) {
+        toggleServer(active) {
             this.config.active = active;
             this.$store.dispatch('configSetActivation', {id: this.config.id, active: active})
             .then(({ data }) => {
diff --git a/vueapp/components/Courses/CoursesSidebar.vue b/vueapp/components/Courses/CoursesSidebar.vue
index ef41bb27c..2be8ee972 100644
--- a/vueapp/components/Courses/CoursesSidebar.vue
+++ b/vueapp/components/Courses/CoursesSidebar.vue
@@ -277,6 +277,15 @@ export default {
             'schedule_list', 'schedule_loading'
         ]),
 
+        isUnderMaintenance() {
+            if (!this.simple_config_list?.settings) {
+                return false;
+            }
+            let config_id = this.simple_config_list.settings['OPENCAST_DEFAULT_SERVER'];
+            let server = this.simple_config_list.server[config_id];
+            return server?.maintenance_mode?.active;
+        },
+
         fragment() {
             return this.$route.name;
         },
@@ -286,7 +295,8 @@ export default {
                 return this.cid !== undefined && // Make sure this is happening in a course!
                     this.currentUser.can_edit && // Make sure the user has sufficient "global" rights.
                     this.simple_config_list['settings']['OPENCAST_ALLOW_SCHEDULER'] && // Make sure it is configured!
-                    this.course_config.scheduling_allowed; // Make sure the user is allowed to schedule recordings in the course!
+                    this.course_config.scheduling_allowed && // Make sure the user is allowed to schedule recordings in the course!
+                    !this.isUnderMaintenance;
             } catch (error) {
                 return false;
             }
@@ -297,14 +307,15 @@ export default {
                 return this.cid !== undefined &&
                     this.currentUser.can_edit &&
                         this.simple_config_list['settings']['OPENCAST_ALLOW_STUDIO'] &&
-                        this.hasDefaultPlaylist;
+                        this.hasDefaultPlaylist &&
+                        !this.isUnderMaintenance;
             } catch (error) {
                 return false;
             }
         },
 
         recordingLink() {
-            if (!this.simple_config_list.settings || !this.course_config || !this.canShowStudio) {
+            if (!this.simple_config_list.settings || !this.course_config || !this.canShowStudio || this.isUnderMaintenance) {
                 return;
             }
 
@@ -324,7 +335,7 @@ export default {
         },
 
         canEdit() {
-            if (!this.course_config) {
+            if (!this.course_config || this.isUnderMaintenance) {
                 return false;
             }
 
@@ -332,7 +343,7 @@ export default {
         },
 
         canUpload() {
-            if (!this.course_config) {
+            if (!this.course_config || this.isUnderMaintenance) {
                 return false;
             }
 
@@ -503,7 +514,6 @@ export default {
     },
 
     async mounted() {
-        this.$store.dispatch('simpleConfigListRead');
         this.semesterFilter = this.semester_filter;
 
         const route = useRoute();
diff --git a/vueapp/components/LtiAuth.vue b/vueapp/components/LtiAuth.vue
index 832fcc9ae..f718baedc 100644
--- a/vueapp/components/LtiAuth.vue
+++ b/vueapp/components/LtiAuth.vue
@@ -68,10 +68,12 @@ export default {
         }
     },
 
-    mounted() {
-        this.$store.dispatch('simpleConfigListRead').then(() => {
-            this.checkLTIPeriodically();
-        });
-    }
+    watch: {
+        simple_config_list(newValue) {
+            if (newValue?.server && this.interval === null) {
+                this.checkLTIPeriodically();
+            }
+        }
+    },
 }
 </script>
diff --git a/vueapp/components/MaintenanceMessage.vue b/vueapp/components/MaintenanceMessage.vue
new file mode 100644
index 000000000..ca8d42134
--- /dev/null
+++ b/vueapp/components/MaintenanceMessage.vue
@@ -0,0 +1,53 @@
+<template>
+    <div v-if="maintenance_infos.length > 0">
+        <MessageBox v-for="maintenance_info in maintenance_infos" type="warning" :html="maintenance_info" />
+    </div>
+</template>
+
+<script>
+import MessageBox from '@/components/MessageBox.vue';
+
+import { mapGetters } from "vuex";
+
+export default {
+    name: "MaintenanceMessage",
+    components: {
+        MessageBox
+    },
+    computed: {
+        ...mapGetters(['simple_config_list']),
+    },
+    data() {
+        return {
+            maintenance_infos: [],
+            watcher_ran: false
+        }
+    },
+
+    methods: {
+        async printMaintenanceInfos() {
+            for (let server_key in this.simple_config_list.server) {
+                let server = this.simple_config_list.server[server_key];
+                if (server?.maintenance_text && server?.maintenance_mode?.active) {
+                    let text = server.maintenance_text ?? '';
+                    if (text) {
+                        let parsed_text = JSON.parse(text);
+                        if (parsed_text?.[this.simple_config_list.user_language]) {
+                            this.maintenance_infos.push(parsed_text[this.simple_config_list.user_language]);
+                        }
+                    }
+                }
+            }
+        }
+    },
+
+    watch: {
+        simple_config_list(newValue) {
+            if (newValue?.server && !this.watcher_ran) {
+                this.printMaintenanceInfos();
+                this.watcher_ran = true;
+            }
+        }
+    },
+};
+</script>
diff --git a/vueapp/components/MessageBox.vue b/vueapp/components/MessageBox.vue
index a3720109c..f32f51001 100644
--- a/vueapp/components/MessageBox.vue
+++ b/vueapp/components/MessageBox.vue
@@ -8,7 +8,12 @@
         </div>
 
         <div>
-            <slot>Message</slot>
+            <template v-if="html">
+                <span v-if="html" class="messagebox-html-container" v-html="html"></span>
+            </template>
+            <template v-else>
+                <slot>Message</slot>
+            </template>
         </div>
     </div>
 </template>
@@ -16,7 +21,7 @@
 <script>
 export default {
     name: "MessageBox",
-    props: ['type'],
+    props: ['type', 'html'],
     methods: {
         hide() {
             this.$emit('hide');
diff --git a/vueapp/components/Playlists/PlaylistAddNewCard.vue b/vueapp/components/Playlists/PlaylistAddNewCard.vue
index c9ac9abef..09d8804e1 100644
--- a/vueapp/components/Playlists/PlaylistAddNewCard.vue
+++ b/vueapp/components/Playlists/PlaylistAddNewCard.vue
@@ -114,11 +114,15 @@ export default {
     },
 
     mounted() {
-        this.$store.dispatch('simpleConfigListRead').then(() => {
-            this.selectedServer = this.simple_config_list['server'][this.simple_config_list.settings['OPENCAST_DEFAULT_SERVER']];
-        })
-
         this.$refs.autofocus.focus();
     },
+
+    watch: {
+        simple_config_list(newValue) {
+            if (newValue?.server && newValue?.settings) {
+                this.selectedServer = newValue['server'][newValue.settings['OPENCAST_DEFAULT_SERVER']];
+            }
+        }
+    },
 }
 </script>
diff --git a/vueapp/components/Videos/Actions/VideoAccess.vue b/vueapp/components/Videos/Actions/VideoAccess.vue
index fa179dbe6..95d350bd9 100644
--- a/vueapp/components/Videos/Actions/VideoAccess.vue
+++ b/vueapp/components/Videos/Actions/VideoAccess.vue
@@ -128,7 +128,7 @@
                             </table>
                         </fieldset>
 
-                        <fieldset v-if="config.settings.OPENCAST_ALLOW_PUBLIC_SHARING">
+                        <fieldset v-if="!isUnderMaintenance && config.settings.OPENCAST_ALLOW_PUBLIC_SHARING">
                             <legend>
                                 {{ $gettext('Weltweiter Zugriff') }}
                             </legend>
@@ -246,6 +246,15 @@ export default {
             }
 
             return this.event?.perm === 'owner' || this.event?.perm === 'write';
+        },
+
+        isUnderMaintenance() {
+            if (this.config?.settings) {
+                return false;
+            }
+            let config_id = this.event?.config_id ?? this.config.settings['OPENCAST_DEFAULT_SERVER'];
+            let server = this.config.server[config_id];
+            return server?.maintenance_mode?.active;
         }
     },
 
diff --git a/vueapp/components/Videos/VideoRow.vue b/vueapp/components/Videos/VideoRow.vue
index d39bc3943..0f9319267 100644
--- a/vueapp/components/Videos/VideoRow.vue
+++ b/vueapp/components/Videos/VideoRow.vue
@@ -385,6 +385,15 @@ export default {
             'course_config'
         ]),
 
+        isUnderMaintenance() {
+            if (this.simple_config_list?.server) {
+                return false;
+            }
+            let config_id = this.event?.config_id ?? this.simple_config_list.settings['OPENCAST_DEFAULT_SERVER'];
+            let server = this.simple_config_list.server[config_id];
+            return server?.maintenance_mode?.active;
+        },
+
         showCheckbox() {
             return this.selectable || (this.canUpload && (this.event.perm == 'owner' || this.event.perm == 'write'));
         },
@@ -469,44 +478,47 @@ export default {
 
             if (!this.event?.trashed) {
                 if (this.event.perm == 'owner' || this.event.perm == 'write') {
-                    if (this.event?.state !== 'running') {
+                    if (!this.isUnderMaintenance) {
+
+                        if (this.event?.state !== 'running') {
+                            menuItems.push({
+                                id: 1,
+                                label: this.$gettext('Bearbeiten'),
+                                icon: 'edit',
+                                emit: 'performAction',
+                                emitArguments: 'VideoEdit'
+                            });
+                        }
+
+                        /*
+                        if (this.playlistForVideos) {
+                            menuItems.push({
+                                id: 3,
+                                label: this.$gettext('Zur Wiedergabeliste hinzufügen'),
+                                icon: 'add',
+                                emit: 'performAction',
+                                emitArguments: 'VideoAddToPlaylist'
+                            });
+                        }
+                        */
+
+                        /*
                         menuItems.push({
-                            id: 1,
-                            label: this.$gettext('Bearbeiten'),
-                            icon: 'edit',
+                            label: this.$gettext('Zu Wiedergabeliste hinzufügen'),
+                            icon: 'add',
                             emit: 'performAction',
-                            emitArguments: 'VideoEdit'
+                            emitArguments: 'VideoLinkToPlaylists'
                         });
-                    }
+                        */
 
-                    /*
-                    if (this.playlistForVideos) {
                         menuItems.push({
                             id: 3,
-                            label: this.$gettext('Zur Wiedergabeliste hinzufügen'),
-                            icon: 'add',
+                            label: this.$gettext('Verknüpfungen'),
+                            icon: 'group',
                             emit: 'performAction',
-                            emitArguments: 'VideoAddToPlaylist'
+                            emitArguments: 'VideoLinkToPlaylists'
                         });
                     }
-                    */
-
-                    /*
-                    menuItems.push({
-                        label: this.$gettext('Zu Wiedergabeliste hinzufügen'),
-                        icon: 'add',
-                        emit: 'performAction',
-                        emitArguments: 'VideoLinkToPlaylists'
-                    });
-                    */
-
-                    menuItems.push({
-                        id: 3,
-                        label: this.$gettext('Verknüpfungen'),
-                        icon: 'group',
-                        emit: 'performAction',
-                        emitArguments: 'VideoLinkToPlaylists'
-                    });
 
                     if (this.canShare) {
                         menuItems.push({
@@ -529,7 +541,7 @@ export default {
                     }
 
                     // As we abandoned the preview object structure, we now have to only validate the preview URL!
-                    if ((this.event?.preview || this.event?.state == 'cutting') && !this.isLivestream) {
+                    if ((this.event?.preview || this.event?.state == 'cutting') && !this.isLivestream && !this.isUnderMaintenance) {
                         menuItems.push({
                             id: 5,
                             label: this.$gettext('Videoeditor öffnen'),
@@ -539,7 +551,7 @@ export default {
                         });
                     }
 
-                    if (this.event?.publication?.annotation_tool && this.event?.state !== 'running') {
+                    if (this.event?.publication?.annotation_tool && this.event?.state !== 'running' && !this.isUnderMaintenance) {
                         menuItems.push({
                             id: 6,
                             label: this.$gettext('Anmerkungen hinzufügen'),
@@ -549,7 +561,7 @@ export default {
                         });
                     }
 
-                    if (this.event?.state !== 'running' && !this.isLivestream) {
+                    if (this.event?.state !== 'running' && !this.isLivestream && !this.isUnderMaintenance) {
                         menuItems.push({
                             id: 7,
                             label: this.$gettext('Untertitel bearbeiten'),
@@ -559,7 +571,7 @@ export default {
                         });
                     }
 
-                    if (!this.isCourse && !this.isLivestream) {
+                    if (!this.isCourse && !this.isLivestream && !this.isUnderMaintenance) {
                         menuItems.push({
                             id: 9,
                             label: this.$gettext('Zum Löschen markieren'),
@@ -569,7 +581,7 @@ export default {
                         });
                     }
 
-                    if (this.canUpload && this.playlist) {
+                    if (this.canUpload && this.playlist && !this.isUnderMaintenance) {
                         menuItems.push({
                             id: 10,
                             label: this.$gettext('Aus Wiedergabeliste entfernen'),
@@ -626,6 +638,10 @@ export default {
         },
 
         canEdit() {
+            if (this.isUnderMaintenance) {
+                return false;
+            }
+
             return this.event?.perm === 'owner' || this.event?.perm === 'write';
         },
 
diff --git a/vueapp/components/Videos/VideoUpload.vue b/vueapp/components/Videos/VideoUpload.vue
index 5f4574b26..9fd593fde 100644
--- a/vueapp/components/Videos/VideoUpload.vue
+++ b/vueapp/components/Videos/VideoUpload.vue
@@ -270,6 +270,15 @@ export default {
             'currentUserSeries' : 'currentUserSeries'
         }),
 
+        isUnderMaintenance() {
+            if (!this.config?.settings) {
+                return false;
+            }
+            let config_id = this.config.settings['OPENCAST_DEFAULT_SERVER'];
+            let server = this.config.server[config_id];
+            return server?.maintenance_mode?.active;
+        },
+
         fragment() {
             return this.$route.name;
         },
@@ -355,7 +364,7 @@ export default {
         },
 
         async accept() {
-            if (this.uploadProgress) {
+            if (this.uploadProgress || this.isUnderMaintenance) {
                 return;
             }
 
@@ -520,12 +529,8 @@ export default {
         }
     },
 
-    mounted() {
-        this.$store.dispatch('authenticateLti');
-        this.$store.dispatch('simpleConfigListRead').then(() => {
-            this.selectedServer = this.config['server'][this.config.settings['OPENCAST_DEFAULT_SERVER']];
-            this.selectedWorkflow = this.defaultWorkflow;
-        })
+    async mounted() {
+        await this.$store.dispatch('authenticateLti');
 
         if (this.cid) {
             this.$store.dispatch('loadCourseConfig', this.cid);
@@ -534,6 +539,18 @@ export default {
         if (this.playlist) {
             this.upload.playlist_token = this.playlist.token;
         }
-    }
+    },
+
+    watch: {
+        config(newValue) {
+            if (newValue?.server && newValue?.settings) {
+                this.selectedServer = newValue['server'][newValue.settings['OPENCAST_DEFAULT_SERVER']];
+                this.selectedWorkflow = this.defaultWorkflow;
+            } else {
+                this.selectedServer = false;
+                this.selectedWorkflow = false;
+            }
+        }
+    },
 }
 </script>
diff --git a/vueapp/components/Videos/VideosSidebar.vue b/vueapp/components/Videos/VideosSidebar.vue
index a6e2070f6..6bb1bc594 100644
--- a/vueapp/components/Videos/VideosSidebar.vue
+++ b/vueapp/components/Videos/VideosSidebar.vue
@@ -136,6 +136,15 @@ export default {
             'currentUser'
         ]),
 
+        isUnderMaintenance() {
+            if (!this.simple_config_list?.settings) {
+                return false;
+            }
+            let config_id = this.simple_config_list.settings['OPENCAST_DEFAULT_SERVER'];
+            let server = this.simple_config_list.server[config_id];
+            return server?.maintenance_mode?.active;
+        },
+
         isDownloadAllowedForPlaylist() {
             if (this.playlist) {
                 if (this.playlist['allow_download'] === null) {
@@ -150,7 +159,7 @@ export default {
 
         canShowStudio() {
             try {
-                return this.currentUserSeries && this.simple_config_list['settings']['OPENCAST_ALLOW_STUDIO']
+                return this.currentUserSeries && this.simple_config_list['settings']['OPENCAST_ALLOW_STUDIO'] && !this.isUnderMaintenance;
             } catch (error) {
                 return false;
             }
@@ -159,7 +168,7 @@ export default {
         canShowUpload()
         {
             try {
-                return this.currentUserSeries
+                return this.currentUserSeries && !this.isUnderMaintenance
                     && (
                         this.simple_config_list['settings']['OPENCAST_ALLOW_STUDENT_WORKSPACE_UPLOAD']
                         || ['root', 'admin', 'dozent'].includes(this.currentUser.status)
@@ -170,7 +179,7 @@ export default {
         },
 
         recordingLink() {
-            if (!this.simple_config_list.settings || !this.canShowStudio) {
+            if (!this.simple_config_list.settings || !this.canShowStudio || this.isUnderMaintenance) {
                 return;
             }
 
@@ -204,9 +213,5 @@ export default {
             return this.simple_config_list?.workflows.find(wf => wf['id'] == wf_id)['name'];
         }
     },
-
-    mounted() {
-        this.$store.dispatch('simpleConfigListRead');
-    }
 }
 </script>
diff --git a/vueapp/composables/useSimpleConfigChecker.js b/vueapp/composables/useSimpleConfigChecker.js
new file mode 100644
index 000000000..1623806ad
--- /dev/null
+++ b/vueapp/composables/useSimpleConfigChecker.js
@@ -0,0 +1,70 @@
+import { ref, watch, computed, onBeforeMount, onBeforeUnmount } from 'vue';
+import { useStore } from 'vuex';
+
+export function useSimpleConfigChecker() {
+    const store = useStore();
+    const simple_config_interval = ref(null);
+
+    const simple_config_list = computed(() => store.getters.simple_config_list);
+
+    async function readSimpleConfigPeriodically() {
+        simple_config_interval.value = setInterval(async () => {
+            await store.dispatch('simpleConfigListRead');
+        }, 7000);
+    }
+
+    onBeforeMount(() => {
+        readSimpleConfigPeriodically();
+    });
+
+    onBeforeUnmount(() => {
+        if (simple_config_interval.value !== null) {
+            clearInterval(simple_config_interval.value);
+        }
+    });
+
+    watch(simple_config_list, (newValue, oldValue) => {
+        // This is the first run!
+        if (JSON.stringify(oldValue) === '{}') {
+            return;
+        }
+
+        let current_default_config_id, current_main_server,
+            new_default_config_id, new_main_server = null;
+        let current_maintenance, current_maintenance_readonly,
+            new_maintenance, new_maintenance_readonly = false;
+
+        if (oldValue?.settings && oldValue?.server) {
+            current_default_config_id = oldValue.settings['OPENCAST_DEFAULT_SERVER'];
+            current_main_server = oldValue.server[current_default_config_id];
+            current_maintenance = current_main_server?.maintenance_mode?.active;
+            current_maintenance_readonly = current_main_server?.maintenance_mode?.read_only;
+        }
+
+        if (newValue?.settings && newValue?.server) {
+            new_default_config_id = newValue.settings['OPENCAST_DEFAULT_SERVER'];
+            new_main_server = newValue.server[new_default_config_id];
+            new_maintenance = new_main_server?.maintenance_mode?.active;
+            new_maintenance_readonly = new_main_server?.maintenance_mode?.read_only;
+        }
+
+        let needs_reload = false;
+        // if the default server has been changed, mostly used for upload and studio etc.
+        if (JSON.stringify(new_main_server) !==  JSON.stringify(current_main_server)) {
+            needs_reload = true;
+        }
+
+        // if maintenance has been changed!
+        if (current_maintenance !== new_maintenance || current_maintenance_readonly !== new_maintenance_readonly) {
+            needs_reload = true;
+        }
+
+        if (needs_reload) {
+            window.location.reload();
+        }
+    });
+
+    return {
+        simple_config_interval
+    };
+}
diff --git a/vueapp/store/config.module.js b/vueapp/store/config.module.js
index 57676674b..f571affa0 100644
--- a/vueapp/store/config.module.js
+++ b/vueapp/store/config.module.js
@@ -7,6 +7,8 @@ const initialState = {
         'service_url' :      null,
         'service_user':      null,
         'service_password':  null,
+        'maintenance_mode':  'off',
+        'maintenance_text':  null,
         'settings': {
             'lti_consumerkey':        null,
             'lti_consumersecret':     null,
@@ -57,13 +59,14 @@ export const actions = {
             });
     },
 
-    async simpleConfigListRead(context) {
-        return new Promise(resolve => {
-            ApiService.get('config/simple')
-                .then(({ data }) => {
-                    context.commit('simpleConfigListSet', data);
-                    resolve(data);
-                });
+    async simpleConfigListRead(context, force_reload = true) {
+        if (force_reload === false && JSON.stringify(context.getters.simple_config_list) !== '{}') {
+            return context.state.simple_config_list;
+        }
+        return ApiService.get('config/simple')
+            .then(({ data }) => {
+                context.commit('simpleConfigListSet', data);
+                return data;
             });
     },
 
diff --git a/vueapp/views/Contents.vue b/vueapp/views/Contents.vue
index 0d7730961..f924ffb7a 100644
--- a/vueapp/views/Contents.vue
+++ b/vueapp/views/Contents.vue
@@ -23,6 +23,8 @@
             @cancel="closePlaylistAddVideosDialog"
         />
 
+        <MaintenanceMessage />
+
         <MessageList />
 
         <router-view></router-view>
@@ -35,6 +37,10 @@ import VideoUpload from "@/components/Videos/VideoUpload";
 import PlaylistAddVideos from "@/components/Playlists/PlaylistAddVideos";
 
 import MessageList from "@/components/MessageList";
+import MaintenanceMessage from "@/components/MaintenanceMessage";
+
+import { useSimpleConfigChecker } from '@/composables/useSimpleConfigChecker';
+
 import { mapGetters } from "vuex";
 
 export default {
@@ -42,7 +48,8 @@ export default {
 
     components: {
         VideosSidebar,      VideoUpload,
-        PlaylistAddVideos,  MessageList
+        PlaylistAddVideos,  MessageList,
+        MaintenanceMessage
     },
 
     computed: {
@@ -116,6 +123,11 @@ export default {
             }
         });
         this.$store.dispatch('loadPlaylists');
+    },
+
+    setup() {
+        useSimpleConfigChecker();
+        return {};
     }
 };
 </script>
diff --git a/vueapp/views/Course.vue b/vueapp/views/Course.vue
index a854effaa..24ae777da 100644
--- a/vueapp/views/Course.vue
+++ b/vueapp/views/Course.vue
@@ -41,6 +41,8 @@
             @cancel="closeChangeDefaultVisibility"
         />
 
+        <MaintenanceMessage />
+
         <MessageList />
 
         <router-view></router-view>
@@ -56,6 +58,9 @@ import MessageList from "@/components/MessageList";
 import PlaylistsLinkCard from '@/components/Playlists/PlaylistsLinkCard.vue';
 import PlaylistAddCard from '@/components/Playlists/PlaylistAddCard.vue';
 import PlaylistEditCard from '@/components/Playlists/PlaylistEditCard.vue';
+import MaintenanceMessage from "@/components/MaintenanceMessage";
+
+import { useSimpleConfigChecker } from '@/composables/useSimpleConfigChecker';
 
 import { mapGetters } from "vuex";
 
@@ -67,7 +72,8 @@ export default {
         PlaylistEditCard, CoursesSidebar,
         VideoUpload, PlaylistAddVideos,
         MessageList,
-        EpisodesDefaultVisibilityDialog
+        EpisodesDefaultVisibilityDialog,
+        MaintenanceMessage
     },
 
     computed: {
@@ -159,6 +165,11 @@ export default {
                 });
             }
         });
+    },
+
+    setup() {
+        useSimpleConfigChecker();
+        return {};
     }
 };
 </script>