Clicking on notes while playing the score can sometimes have the score be in a not-playing state
commit e523aad on Linux.
1. open -> demos -> Reunion (or any other score).
2. Play (space)
3. click on any note
Result: Sometimes, the UI (palettes, toolbars) doesn't stay grayed out, but the score still plays.
So far, it seems to me that the chance of getting this to happen is hit-or-miss.
Tried on 2.0.3 AppImage. Rarely happens and also no obvious cause, but possible. (seems to be much more frequent with master)