A crash occurs every time I do the following, with the MusE master appimage:
Open new, empty project.
Add midi track.
Add midi part.
Start cutting it in pieces n times.
Undo m times.
Repeat until MusE crashes. Won't take too long.
I'd attach the coredump if it weren't 340MB in size..
I haven't yet been able to reproduce this crash with the 4.1 appimage.