Viewer and Editor have stopped working in Calibre

Viewer and Editor have stopped working in Calibre.
If I try to open an epub nothing happens. View or Edit book.

Im running a desktop(too old for win11) with windows 10.
I don't know what version this started with. I usually just use calibre for loading my kobo and that still works fine. It used to work fine though.

calibre-debug -w
---------------
QPA platform: windows
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 81.55183946488295 x 81.64285714285714
ApplicationPaletteChange event ignored
Using calibre Qt style: True
ApplicationPaletteChange event received
Sandboxing disabled by user.

I tried downloading the calibre portable version, still doesn't work.

I tried starting windows in safe mode, and then the viewer now works, but only in safe mode, back in regular mode it does not work.

Thanks for any help.