Musescore 3.6.2 crashes on opening

I'm a generally happy MuseScore user, running MuseScore 3.6.2 on a MacBook Air, operating on MacOS Catalina. Tonight I've tried to open MuseScore: the program opens, including, briefly, the window showing my recent files, and then without comment or warning it closes down. I've tried to run the program a couple of times, same result each time.
This happened immediately after I'd run a software update.
Any advice, please?
David G