Musescore abruptly stopped opening (But seems to be still running?)

First want to say that I love this program, I use it professionally and for fun.

The only thing I did unusual was leave a file open on my computer for a long period of time, maybe >24 hours. I opened and closed my laptop several times during this time period.

The file was nothing unusual. just a single organ part, two staves, no strange bugs happened while I was working on it.

Now Musescore just won't open any file. It displays the splash screen, but then the program window never appears. But this is the weird part- it's like the program is still open. If I push the up and down arrows, the notes still play, like I'm moving notes up and down on the staff. The program appears to be open on the taskbar. The screen is nowhere to be found.

I am running windows 7, 64 bit. I was running musescore 1.1 when the issue arose. I uninstalled it and downloaded 1.2, but it's the same problem and symptoms as before. I searched for this problem on the forums but found nothing. I have tried restarting/shutting down the computer several times. The problem persists with all my musescore files.

Any help hugely appreciated! I use this program for work. Thanks!

Robert