MouseMaster Extension "module is not loaded"

[jamie.miller.phd]

Problem report for 3D Slicer 5.12.3 win-amd64: Trying to use the MouseMaster extension, but after downloading from extension manager, and installing from file, there is a error message in the module finder “MouseMaster module is not loaded”

Any help with this one would be greatly appreciated.

[jamie.miller.phd]

From Logs; [CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - Traceback (most recent call last):

[CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - File “”, line 1, in

[CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - File “<frozen importlib._bootstrap_external>”, line 999, in exec_module

[CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - File “<frozen importlib._bootstrap>”, line 488, in _call_with_frames_removed

[CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - File “C:/Users/milleja1/AppData/Local/slicer.org/3D Slicer 5.12.3/slicer.org/Extensions-34627/MouseMaster/lib/Slicer-5.12/qt-scripted-modules/MouseMaster.py”, line 14, in

[CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - from MouseMasterLib import MouseMasterEventHandler, PresetManager

[CRITICAL][Stream] 09.09.2026 10:49:42 [] (unknown:0) - ModuleNotFoundError: No module named ‘MouseMasterLib’

[CRITICAL][Qt] 09.09.2026 10:49:42 [] (unknown:0) - loadSourceAsModule - Failed to load file “C:/Users/milleja1/AppData/Local/slicer.org/3D Slicer 5.12.3/slicer.org/Extensions-34627/MouseMaster/lib/Slicer-5.12/qt-scripted-modules/MouseMaster.py” as module “MouseMaster” !

[CRITICAL][Qt] 09.09.2026 10:49:42 [] (unknown:0) - Fail to instantiate module “MouseMaster”

[jamesobutler (James Butler)]

@benzwick It looks like you forgot to include in the CMake infrastructure the MouseMasterLib of files.

https://github.com/benzwick/SlicerMouseMaster/blob/9bebc08d1339f1bfeb90b7168c203a8d8f408e19/MouseMaster/CMakeLists.txt#L2-L11

[benzwick]

Thanks @jamie.miller.phd and @jamesobutler - I will try to fix this.