1 Major Bug, 1 Minor
MuseScore 3.4.2, Revision 148e43f (should be most recent).
Windows 10 Home, Version 1903
These seem to be only on my end, but I have no idea how to fix them.
1 (Major) - Ever since an update or two after MuseScore 3 was released (i.e., a year or two, iirc), my program crashes ANY time I go to save or open a score. Making a new file works, and I can work on it, but in order to save the file, I have to quickly hit "Save" or "Save as" and click save with whatever it gives me, before it crashes. I assume this has to deal with the file program or something along those lines. I can't directly rename a file from MuseScore, that I named wrong, nor can I actually properly save what I am working with. Uninstall and fresh reinstall does not appear to work. I haven't properly made any music on here in a while due to it.
2 (Minor) - MuseScore 3 score files seem to be originally saved as ".mscz,", which is the wrong filename save. It should still be ".mscz", like MuseScore 2, in order to play.
I haven't seen anyone else with my issues, so I can't say for certain what it is.