Keeps crashing when I try to delete tempo markings

To preface, this score was created on Musescore 3, and I'm now using 4 (fully updated-- I checked), so I don't know if that's what's causing the problem. But there's a tempo marking I have at the beginning of my song that I can't edit or delete. When I double-clicked on it to change the tempo from 110 to 130, it didn't respond. Musescore had crashed/wigged out for me previously in the same session, so I left it for literally almost an hour, and Musescore still never responded. I went back and tried it twice more-- same results. So I just tried clicking it once and deleting it. Also crashed Musescore. I don't really know how to stop this from happening because everything else is working (though the palette search option gave me trouble, too). It's not a network issue, I'm pretty sure, because nothing else on my computer is having trouble running. Is anyone else having this problem/know a solution?