Can't open a musescore file

I should preface this by saying that a little while ago, I lost my progress when my musescore crashed. I was pissed at the time, but learned my lesson and have since been obsessively saving my projects every couple of minutes.

Last night, I created a new project and worked on it for a few hours. This morning, my computer restarted. When I went to open my file, I got a pop-up saying that musescore 'Could not read the file'. I went to the forums for advice and...

1. Looked through the autosaves (did all the stuff necessary to 'show hidden files', the only relevant backup I have is of a project I had open in a separate tab WHILE I WAS WORKING on the lost project).

2. Tried uploading it to the website in the hopes that I could redownload it. Same error.

3. Sent it to a friend with musescore. Honestly, that was a last ditch attempt.

Nothing. I'm especially miffed by the autosave thing, because I haven't messed with the defaults and worked on that file for well over three hours.

I'm running musescore 2.1 on Windows 10. 2.1 is the only version I've ever downloaded (I only just came upon musescore recently).

I'll admit I'm quite angry about this, in large part because I made a few extremely important sacrifices to get a head start on that project. Most of the forum topics I can find are from a while back and say things about how the problem would be fixed in 2.0.3 and 2.1, which...well, I'm running 2.1. I've only EVER run 2.1. I saved all my work every couple of seconds expressly to avoid this sort of fiasco. The closest thing I can find to an explanation is someone (forget which topic) saying that the file may have been corrupted upon creation, which...well.

If anyone has any other hail marys it sounds like I haven't tried, I welcome it. I'd like my three hours back.