Musescore 4 deleted my file

I opened my score in MuseScore 4 and opened it in MuseScore 3 to see what the differences are. As soon as I did that with MuseScore 3, it notified me that this file is defaulted to MuseScore 4 and proceeded to delete the entire contents of my score. Please, is there a way to revert my file in my MacBook Pro? I've been working on this score for months!