Score preview shows correctly, score opens without errors, but no score is visible.
Using MuseScore 2.0.2, revision f51dc11, I created a score, 4 parts, modified it, saved it, etc. I saved it to a network drive. I then closed MuseScore, and a few minutes later decided to make one more edit before heading to bed for the night. I opened the .mcsz file (no file with an extension ending in a comma was present), but the score did not display. I closed all the open files (I had set MuseScore to restore my previous session). I closed MuseScore. I opened MuseScore. The score in question shows in the Start Center, and the thumbnail appears correct. However, if I open it, it still shows no data. See the attached screenshots.
I made a copy of the .mcsz file, renamed it to .zip, and unzipped it with 7-zip. The unzip resulted in a file and directory structure, but there were a couple of errors saying "unsupported compression method for" the thumbnail and the .mscx file. I tried on a file I knew opened correctly, and did not get the errors, but also did get the thumbnail as displayed in the Start Center. I tried making a copy of the file and moving it somewhere else. No change. I checked %USERPROFILE%\AppData\Local\MuseScore\MuseScore2 for a backup file but the only ones I found were from last fall, and though openable, were not the score I'm looking for.
Clearly the thumbnail for my new score was generated correctly at some point, and the .mcsz file is not zero bytes, so, without having to print a screenshot of the thumbnail and use a magnifying glass, or without having to download the source, compile, and debug (I program for my day job, music is what I'm not paid to do), how do I go about recovering the data?