MuseScore 3.6.0 is crashing a lot

Hi - I've used MuseScore for some years, but recently lots of crash reports when I try to open files I was just editing minutes earlier. I can't figure out the pattern.

I get pop-up window: MuseScore Crash Reporter

Message: Unfortunately MuseScore has crashed. Would you like to send a report to make it possible for us to fix the problem?
Please describe your actions when the crash occurred (optional).

Starting up a file into MuseScore sometimes gives this (either answer gives the above error):
MuseScore: The previous session quit unexpectedly.
Restore session?
[ Yes ] [ No ]

MuseScore vs 3.6.0
Windows 10

I went back to factory defaults, but it still crashes - sometimes for some files - but more and more.

It even happens for files I was in ok with and saved (days or minutes ago), then just opened up again to view and listen.

I do copy existing files to start other new songs, so there might possibly be a single problem that propagated throughout all my files in this batch.

Testing, it even happens on files I created years ago.

I have tried to open files in MuseScore:
- Double-click Compresses MuseScore file to start MuseScore (errors above)
- Start MuseScore (ok) then Menu > Open > folder > file > Select (MuseScore disappears)

Please let me know any way I can get MuseScore working reliably again.

Thank you,
Bruce - coesongs@yahoo.com