I tried a lot of things:
- scf /scannow- DISM /Online /Cleanup-Image /RestoreHealth
- Disabling Excel add-ins.
- Removing any files (xlsb) in Excel temp.
- Disabling GPU acceleration/multi-threaded processes.
Event Viewer says: Faulting module name: ntdll.dll
ntdll.dll is responsible for a few things like memory management, error handling, etc.I got the exception error code c0000374 which indicates a heap corruption error, meaning memory corruption, bad drivers, or software conflicts.
Heap corruption errors can be caused by many system-level things like corrupt updates, but running both mentioned commands would have solved this if so.
What actually worked: running Excel in Win 8 compatibility mode.
I found when it crashed it was trying to find:
HKCU\Software\Classes\Wow6432Node\CLSID\{7B8A2D94-0AC9-11D1-896C-00C04FB6BFC4}
So, perhaps Win 8 compat. mode looked elsewhere for this (HKLM), and the CLSID existed there.
Merging this across to HKCU alone didn't fix the issue if ran w/o Win8 compat. mode so I guess there is a lot more to this; maybe there are other missing reg paths, or the compatibility mode bypasses security checks, maybe older DLLs in use also.