Addon manager crash after Ribbon install - Windows 11

[samsterckval]

Describe the bug
After install Ribbon add-on, the Addon manager crashes with an empty "Ciritical error" pop-up.
Windows 11.

To Reproduce
Steps to reproduce the behavior:

1. Install Ribbon
2. Restart FreeCAD (generate everything needed)
3. Open Addon Manager
4. See error

Expected behavior
Addon manager to open without error

Screenshots
--> uploads fail, I will try to add

Please complete the following information:

• OS: Windows 11
• FreeCAD information:
  OS: Windows 11 build 26200
  Architecture: x86_64
  Version: 1.1.1.20260414 (Git shallow)
  Build date: 2026/04/14 22:09:59
  Build type: Release
  Branch: (HEAD detached at 0108fd4b4)
  Hash: 0108fd4b4850cc46e625b60e53cea7a7bbe69f8d
  Python 3.11.15, Qt 6.8.3, Coin 4.0.3, Vtk 9.3.1, boost 1_86, Eigen3 3.4.0, PySide 6.8.3
  shiboken 6.8.3, xerces-c 3.3.0, IfcOpenShell 0.8.4, OCC 7.8.1
  Locale: English/Belgium (en_BE)
  Navigation Style/Orbit Style/Rotation Mode: CAD/Rounded Arcball/Window center
  Stylesheet/Theme/QtStyle: FreeCAD.qss/FreeCAD Dark/
  Logical DPI/Physical DPI/Pixel Ratio: 96/108.888/1
  Installed mods:

• FreeCAD-Ribbon 1.11.0

• Ribbon information (Develop version only):
  Installed version: 1.11.0
  Branch: -
  Commit ID: -
• Export your layout, zip it and add it to your issue by dragging it or use the button below.

Additional context
Somehow, when this happens, windows explorer also seems to hang.

[samsterckval]

Information from the FreeCAD log:

Log: Checking network connection...
Log: FreeCAD Addon server response: OK

Msg: Found additional branch 'development' for addon AddonManager
Msg: Unrecognized license string 'LGPLv2.1' normalized to SPDX license ID 'LGPL-2.1' for addon 'BCF Plugin'Msg: 
Msg: Found additional branch 'Develop' for addon BillOfMaterials
Msg: Unrecognized license string 'LGPLv2.1' normalized to SPDX license ID 'LGPL-2.1' for addon 'boltsfc'Msg: 
Msg: Found additional branch 'Latest' for addon Cubinets
Msg: Unrecognized license string 'AGPLv3.0' normalized to SPDX license ID 'AGPL-3.0' for addon 'Defeaturing Workbench'Msg: 
Msg: Unrecognized license string 'LGPLv3' normalized to SPDX license ID 'LGPL-3.0' for addon 'Dodo'Msg: 
Msg: Unrecognized license string 'LGPLv2.1' normalized to SPDX license ID 'LGPL-2.1' for addon 'ElectroMagnetic Workbench'Msg: 
Msg: Found additional branch 'Latest' for addon Motion-Control
Log: Found installed addon 'FreeCAD-Ribbon' with branch 'main'
Msg: Found additional branch 'Develop' for addon FreeCAD-Ribbon
Msg: Unrecognized license string 'lgpl-2.1-or-later' normalized to SPDX license ID 'LGPL-2.1-or-later' for addon 'Gridfinity Workbench'Msg: 
Msg: Unrecognized license string 'AGPLv3.0' normalized to SPDX license ID 'AGPL-3.0' for addon 'KicadStepUp Workbench'Msg: 
Msg: Found additional branch 'Latest' for addon Launcher
Msg: Found additional branch 'Latest' for addon Machines
Msg: Unrecognized license string 'LGPL-3' normalized to SPDX license ID 'LGPL-3.0' for addon 'Maker Workbench'Msg: 
Msg: Unrecognized license string 'GPLv3.0' normalized to SPDX license ID 'GPL-3.0' for addon 'Manipulator Workbench'Msg: 
Msg: Unrecognized SPDX license ID specified for addon 'MOOC': 'GPLv2.1'Msg: 
Msg: Unrecognized license string 'GPL-3' normalized to SPDX license ID 'GPL-3.0' for addon 'NikraDAP'Msg: 
Msg: Unrecognized license string 'AGPLv3.0' normalized to SPDX license ID 'AGPL-3.0' for addon 'FreeCAD-PCB'Msg: 
Msg: Found additional branch 'Latest' for addon Plot
Msg: Found additional branch '1.0.X' for addon Plot
Msg: Found additional branch 'Latest' for addon Pyramids-and-Polyhedrons
Msg: Found additional branch 'Develop' for addon SaveAndRestore
Msg: Unrecognized SPDX license ID specified for addon 'SearchBar': 'CCOv1'Msg: 
Msg: Unrecognized SPDX license ID specified for addon 'SearchBar': 'CCOv1'Msg: 
Msg: Found additional branch 'Develop' for addon SearchBar
Msg: Uncaught exception:
   File "D:\FreeCAD 1.1\Mod\AddonManager\.\addonmanager_workers_startup.py", line 706, in run
    details += f"{addon.display_name} is missing addons {', '.join(deps.external_addons)}\n"
                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

TypeError: sequence item 0: expected str instance, Addon found
Traceback (most recent call last):
  File "D:\FreeCAD 1.1\Mod\AddonManager\.\addonmanager_workers_startup.py", line 706, in run
    details += f"{addon.display_name} is missing addons {', '.join(deps.external_addons)}\n"
                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: sequence item 0: expected str instance, Addon found
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread
Wrn: QBasicTimer::stop: Failed. Possibly trying to stop from a different thread

[samsterckval]

Temporary fix to get things running again:

if deps.external_addons:
    entries = [a if isinstance(a, str) else f"<{type(a).__name__}>" for a in deps.external_addons]
    details += f"{addon.display_name} is missing addons {', '.join(entries)}\n"
if deps.python_requires:
    details += f"{addon.display_name} is missing python packages {', '.join(deps.python_requires)}\n"
self.missing_dependencies.join(deps)

[samsterckval]

I guess this is actually a FreeCAD bug, and the problem came up because I had missing dependencies for Ribbon. If you could confirm this, I report this bug to FreeCAD.

[APEbbers]

Hi,

I was thinking the same thing. The Ribbon seems to be loaded just fine. The save and restore wb and the searchbar as well. It seems to fall over another workbench.