When I click on the WB button, it produces an error

[raindropsfromsky]

Describe your issue

After launching FreeCAD, if I click on the Quetzal WB button, I face this error:

This happens only once per session.
If I click on any other WB button, and then click on the Quetzal button, the error does not repeat.

FreeCAD version info + Quetzal WB version

OS: Windows 11 build 26200
Architecture: x86_64
Version: 1.2.0dev.20260407 (Git shallow)
Build date: 2026/04/07 22:56:13
Build type: Release
Branch: (HEAD detached at 6db886fe0)
Hash: 6db886fe0e79bf060ffeaa50198da25702a17e31
Python 3.11.15, Qt 6.8.3, Coin 4.0.8, 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 0.8.2, OCC 7.8.1
Locale: English/India (en_IN)
Stylesheet/Theme/QtStyle: OpenDark.qss/OpenDark/
Navigation Style/Orbit Style/Rotation Mode: Blender/Trackball/Drag at cursor
Logical DPI/Physical DPI/Pixel Ratio: 96/123.928/1.14583
Installed mods:
  * Cables Workbench 0.3.5
  * Curved Shapes 1.0.14
  * Curves workbench 0.6.71
  * Defeaturing Workbench 1.3.1
  * Fasteners Workbench 0.5.50
  * FreeCAD Ribbon 1.11.0dev
  * OpenTheme 2025.5.20
  * Quetzal 1.8.9
  * SaveAndRestore 0.2.2
  * SearchBar 1.8.0
  * SheetMetal Workbench 0.8.10
  * Silk workbench 0.2.2
  * A Workbench Organizer 2024.1.29

What is the feature affected?

None

Steps to reproduce

1. Launch FreeCAD
2. Click on Quetzal button. The error appears.
3. Click on any other WB, and then click on the Quetzal button again. This time, there is no error.
4. Close FreeCAD.
5. Repeat steps 1-3. The same pattern repeats.

What was the expected result?

This error should not be there.

Put here any screenshots or videos (optional)

No response

Would you like to work on this issue?

None