Install only default apps and Crewchief, then start AC from steam. If Crewchief isn't available in options there should be an error in log.txt with some indication why it is not loading the app. Some "errors" are valid when app is disabled.
Your previous errors like: "ERROR: Python ERROR LOADING MODULE :sys.path.append('apps/python/Sidekick')"
This could be OS/Language related as some use of sys.path.append functions fail in certain combos.
(but this should not change over time, so it then should relate to something else)
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I have done exactly that, defaults + Crewchief, no go. The error is as follows:
Initialising Python Interface
Cleaning Python Cache in path apps/python/system/
LOADING 4 PY APPS
ERROR: Python [ERROR] File apps/python/acnotify/acnotify.py not found
Cleaning Python Cache in path apps/python/Chat/
Opening PyModule Chat
Init PyPlugin:Chat
WARNING: TaskBarIcon :: COULD NOT FIND TEXTURES FOR Python Chat_ICON
'module' object has no attribute 'acUpdate'
'module' object has no attribute 'acShutdown'
Cleaning Python Cache in path apps/python/CrewChiefEx/
Opening PyModule CrewChiefEx
ERROR
PyModule :: Errors occurred loading CrewChiefEx
[PY ERROR]: apps/python/CrewChiefEx\CrewChiefEx.py (17)
ERROR: Python ERROR LOADING MODULE :sys.path.append('apps/python/CrewChiefEx')
Cleaning Python Cache in path apps/python/gMeter/