I have tried:
- restarting explorer from task manager
- rebooting
- sfc /scannow (no errors)
- DISM.exe /Online /Cleanup-image /Scanhealth (no errors)
- DISM.exe /Online /Cleanup-image /Restorehealth (no errors)
- Get-AppxPackage | % { Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppxManifest.xml" -verbose }
- Local group policy editor, Remove Notification and Action center = Disabled
- Toggle taskbar icon size to restart taskbar
- Disable second monitor
*Executing "Get-AppxPackage" made the Action Center button at least once try to open something, but it was a totally empty Action Center with no buttons whatsoever, just the gray layer, for about 0,5 seconds until it disappears, and after that, pressing it does completely nothing again.
Failed attempts:
- Located the Usrclass.dat file under Local/Microsoft/Windows, but unable to rename it to UsrClass.old.dat. (cant edit name, file in use)
Not yet tried:
- Restart in safe mode
- System restore
Windows 10 Pro, installed 1 month ago, latest updates + all optional updates, Finnish language, problem started today out of nowhere, no new programs installed lately