MS4.3 corrupting scores

My original composition (attached below) seems to have been corrupted after a small revision I made yesterday. After clicking the play button on MuseSore Studio, it turns into the pause one for a split second, before becoming the play button again; it stays silent the whole time, and does the same thing no matter how many times I click it. All uploads of this score to Scusemore.com lead to a "Page not found", despite showing in my score manager with thumbnails, as well as allowing me to edit their information. After downloading someone else's score with the same problem, MuseSore Studio wouldn't open any files, crashing whenever I tried to open them; reinstalling seems to have fixed the problem, but the scores mentioned above are still corrupted. I had similar problems, and sometimes the same, on MS4.0 and .1; if you need the scores in question, ask https://musescore.org/en/user/2773989 because I didn't keep them. I never experienced such problems on .2 or .3 until yesterday, and apparently I'm not the only one with this problem. I'm using MS4.3 with Windows 11. Any idea why this might be happening? First they break the website, now it's time to break the software...