Phobos fails to enable on Blender 5.0 (Windows 11)

[uvinay987]

Describe the bug
Phobos v2.0.2 installs successfully (dependencies are downloaded) but fails to enable after restarting Blender 5.0 on Windows 11. The addon appears in the add-ons list but cannot be activated.

Terminal output on first install (via in-built Blender Console):

Python: Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender 5.0\5.0\scripts\addons_core\bl_pkg\bl_extension_ops.py", line 1502, in execute
    cmd_batch = self.exec_command_iter(is_modal)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\Blender Foundation\Blender 5.0\5.0\scripts\addons_core\bl_pkg\bl_extension_ops.py", line 2593, in exec_command_iter
    self.exec_legacy(source_filepath)
  File "C:\Program Files\Blender Foundation\Blender 5.0\5.0\scripts\addons_core\bl_pkg\bl_extension_ops.py", line 2726, in exec_legacy
    bpy.types.PREFERENCES_OT_addon_install.execute(self, bpy.context)
  File "C:\Program Files\Blender Foundation\Blender 5.0\5.0\scripts\startup\bl_operators\userpref.py", line 830, in execute
    bpy.ops.preferences.addon_enable(module=mod.__name__)
  File "C:\Program Files\Blender Foundation\Blender 5.0\5.0\scripts\modules\bpy\ops.py", line 109, in __call__
    ret = _op_call(self.idname_py(), kw)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: Error: All Phobos requirements have been installed.
Please restart Blender to activate the Phobos add-on!

To Reproduce
Steps to reproduce the behavior:

1. Download phobos.zip from the latest GitHub release.
2. Open Blender 5.0 on Windows 11.
3. Go to Edit → Preferences → Add-ons → Install from Disk and select phobos.zip.
4. Enable the Phobos addon — wait for the "requirements installed" popup, then restart Blender as instructed.
5. After restart, attempt to enable Phobos again from the Add-ons list.
6. See error that the addon fails to enable (checkbox does not stay checked, no UI panel appears).

Expected behavior
Phobos should enable successfully after the dependency install + restart cycle, and the Phobos panel should appear in the 3D Viewport sidebar.

Screenshots

Desktop (please complete the following information):

• OS: Windows 11
• Blender version: 5.0.1
• debugging output (setup.py --info): N/A (addon installed via zip, not via setup.py).

Please let me know if I missed anything

[andygang]

降低你的blender版本，使用官方推荐版本号

[brean]

I tested a bit today and was successful to install Phobos from the master-branch with Blender 5.1.2 on Windows 11.
Just zip the phobos-folder from the main repo and install that zip file.

The message

"All Phobos requirements have been installed. Please restart Blender to activate the Phobos add-on!"

Always appears whenever any import fails, which is super misleading.

On my machine I could reproduce your issue by killing blender while it was installing the dependencies (that lead to a state where the "trimesh"-package could not get installed, as numpy was not allowed to get installed in the blender-python-packages folder, which ended up with strange rights after the failed installation, so an issue with permissions).

Removing Blender completely using the installation wizard and deleting the blender "appdata/roaming/Blender Foundation"-folder for my user fixed this for me as I assume it reset the permissions, but I am not sure if that's also the solution for you as there might be other reasons why it could not get imported.

I hope this workaround helps but in general this error message is very misleading and we should definitely give more context with it to make it easier to debug.

[brean]

降低你的blender版本，使用官方推荐版本号

we are working on a new phobos release, we are still testing but so far the current master-branch looks good and works with blender 5.1.2

[uvinay-git]

@brean Thanks for letting us know