diff --git a/arho_feature_template/core/lambda_service.py b/arho_feature_template/core/lambda_service.py
index c32171a..afe0898 100644
--- a/arho_feature_template/core/lambda_service.py
+++ b/arho_feature_template/core/lambda_service.py
@@ -3,7 +3,7 @@
 import json
 import re
 from http import HTTPStatus
-from typing import cast
+from typing import Callable, cast
 
 from qgis.PyQt.QtCore import QByteArray, QObject, QUrl, pyqtSignal
 from qgis.PyQt.QtNetwork import QNetworkAccessManager, QNetworkProxy, QNetworkReply, QNetworkRequest
@@ -15,6 +15,7 @@
 class LambdaService(QObject):
     jsons_received = pyqtSignal(dict, dict)
     validation_received = pyqtSignal(dict)
+    validation_failed = pyqtSignal()
     ActionAttribute = cast(QNetworkRequest.Attribute, QNetworkRequest.User + 1)
     ACTION_VALIDATE_PLANS = "validate_plans"
     ACTION_GET_PLANS = "get_plans"
@@ -57,10 +58,28 @@ def _is_api_gateway_request(self) -> bool:
         match = re.match(r"^https://.*execute-api.*amazonaws\.com.*$", self.lambda_url)
         return bool(match)
 
+    def _get_response_handler(self, action: str) -> Callable[[dict], None]:
+        handlers = {
+            self.ACTION_GET_PLANS: self._process_json_reply,
+            self.ACTION_VALIDATE_PLANS: self._process_validation_reply,
+        }
+        return handlers[action]
+
+    def _get_error_handler(self, action: str) -> Callable[[], None]:
+        handlers = {
+            self.ACTION_GET_PLANS: lambda: None,
+            self.ACTION_VALIDATE_PLANS: self._handle_validation_error,
+        }
+        return handlers[action]
+
     def _handle_reply(self, reply: QNetworkReply):
+        action = reply.request().attribute(LambdaService.ActionAttribute)
+        response_handler = self._get_response_handler(action)
+        error_handler = self._get_error_handler(action)
         if reply.error() != QNetworkReply.NoError:
             error = reply.errorString()
-            QMessageBox.critical(None, "API Error", f"Lambda call failed: {error}")
+            QMessageBox.critical(None, "API Virhe", f"Lambda kutsu epäonnistui: {error}")
+            error_handler()
             reply.deleteLater()
             return
 
@@ -72,7 +91,8 @@ def _handle_reply(self, reply: QNetworkReply):
                 # If calling the lambda directly, the response includes status code and body
                 if int(response_json.get("statusCode", 0)) != HTTPStatus.OK:
                     error = response_json["body"] if "body" in response_json else response_json["errorMessage"]
-                    QMessageBox.critical(None, "API Error", f"Lambda call failed: {error}")
+                    QMessageBox.critical(None, "API Virhe", f"Lambda kutsu epäonnistui: {error}")
+                    error_handler()
                     reply.deleteLater()
                     return
                 body = response_json["body"]
@@ -80,22 +100,20 @@ def _handle_reply(self, reply: QNetworkReply):
                 body = response_json
 
         except (json.JSONDecodeError, KeyError) as e:
-            QMessageBox.critical(None, "JSON Error", f"Failed to parse response JSON: {e}")
+            QMessageBox.critical(None, "JSON Virhe", f"Vastauksen JSON-tiedoston jäsennys epäonnistui: {e}")
+            error_handler()
             return
         finally:
             reply.deleteLater()
+        response_handler(body)
 
-        action = reply.request().attribute(LambdaService.ActionAttribute)
-        if action == self.ACTION_GET_PLANS:
-            self._process_json_reply(body)
-        elif action == self.ACTION_VALIDATE_PLANS:
-            self._process_validation_reply(body)
+    def _handle_validation_error(self):
+        self.validation_failed.emit()
 
     def _process_validation_reply(self, response_json: dict):
         """Processes the validation reply from the lambda and emits a signal."""
 
         validation_errors = response_json.get("ryhti_responses")
-
         self.validation_received.emit(validation_errors)
 
     def _process_json_reply(self, response_json: dict):
diff --git a/arho_feature_template/gui/docks/validation_dock.py b/arho_feature_template/gui/docks/validation_dock.py
index 9658d1c..575df9f 100644
--- a/arho_feature_template/gui/docks/validation_dock.py
+++ b/arho_feature_template/gui/docks/validation_dock.py
@@ -29,6 +29,7 @@ def __init__(self, parent=None):
 
         self.lambda_service = LambdaService()
         self.lambda_service.validation_received.connect(self.list_validation_errors)
+        self.lambda_service.validation_failed.connect(self.enable_validation)
         self.validate_button.clicked.connect(self.validate)
 
     def validate(self):
@@ -48,15 +49,25 @@ def validate(self):
 
         self.lambda_service.validate_plan(active_plan_id)
 
+    def enable_validation(self):
+        """Hide progress bar and re-enable the button"""
+        self.progress_bar.setVisible(False)
+        self.validate_button.setEnabled(True)
+        self.validation_result_tree_view.expandAll()
+        self.validation_result_tree_view.resizeColumnToContents(0)
+
     def list_validation_errors(self, validation_json):
         """Slot for listing validation errors and warnings."""
+
         if not validation_json:
             iface.messageBar().pushMessage("Virhe", "Validaatio json puuttuu.", level=1)
+            self.enable_validation()
             return
 
-        if not validation_json:
-            # If no errors or warnings, display a message and exit
+        # If no errors or warnings, display a message and exit
+        if not any(validation_json.values()):
             iface.messageBar().pushMessage("Virhe", "Ei virheitä havaittu.", level=1)
+            self.enable_validation()
             return
 
         for error_data in validation_json.values():
@@ -79,8 +90,5 @@ def list_validation_errors(self, validation_json):
                     warning.get("message", ""),
                 )
 
-        # Hide progress bar and re-enable the button
-        self.progress_bar.setVisible(False)
-        self.validate_button.setEnabled(True)
-        self.validation_result_tree_view.expandAll()
-        self.validation_result_tree_view.resizeColumnToContents(0)
+        # Always enable validation at the end
+        self.enable_validation()