Can't open file, always crashes Musecore 4 - please help!

I was working on a new file in Musescore 4 and saving it every couple of minutes, when suddenly the app crashed. Trying to re-open this file crashes the app. I can open other files, just not this one. It wasn't large by any means, but was using all the standard MuseHub sounds.
I have restarted the app, restarted my computer, checked for updates both app and system (none), reinstalled the app, duplicated the file, compressed the file, dragged and dropped, opened the file within the app's Recently Opened menu, opened within Finder ... all the usual things you would try and yet nothing is working or even achieving a different result.
Absolutely nothing works for this particular file - doesn't display a corrupted error, the app just quits as soon as I try to open it. All other files I have tried work.
This file was created in Musescore 4 so I can't open it in Musescore 3.
Any help would be appreciated! I was really quite happy with how it was turning out and was my first foray back into composing after months of writer's block :(