MuseScore not opening score

I had (have, I guess) a score called Androsierberg_IX. The file I am trying to open isn't a backup file, and it doesn't have the period before the name or the comma in the file type (i.e. .Androsierberg_IX.mscz,). I'm sure the date posted is somewhere on here, but for convenience's sake, I'm posting this on June 1, 2018. Yesterday (which would be May 31, 2018), I worked on this file until about 2.30 p.m. CDT, and it seemed to work perfectly. I know that I had saved and closed the file before closing MuseScore, so that shouldn't have caused the issue. Did the file just simply get corrupted and now I have to start over, or is there an easier way out? Oh, and I just got a Pro account and was planning to add this score to my scores online, if that helps any of you identify the problem. Please let me know what happened as soon as possible, I'm really worried as this is probablymy best score!

-simplyfrozenwater

(I've also attached the file, which for some reason it let me do even though it won't let me open it in MuseScore. Good luck!)