Crash when closing score during playback (0.9.6.1 regression)
Steps to reproduce bug
1. Open two or more scores in MuseScore
2. Press play
3. While score is still playing, click to close the current tab
MuseScore version: Tested using r. 3272 nightly build. Bug not present in 0.9.6 stable.
(Operating System: Windows 7)