Musescore 4.0 won't run on Wayland (Linux)
S2 - Critical
1) Install Wayland as Flatpak or AppImage
2) Run it using the Wayland backend
Simply put, Musescore 4.0 won't work under Wayland, and that's a major regression from version 3.6
I ran Musescore 4.0 using the Manjaro's distro package on Manarjo linux, and it runs almost fine under Wayland. The one glitch I encountered was that menus appear in the center of the screen instead of appearing attached to the menu bar. I verified (using xwininfo) that Musescore was not running under XWayland when this occurs. I then worked around this bug by changing my launcher to set WAYLAND_DISPLAY= to force Musescure to use XWayland, which fixed the menu bug.
As the bug reporter noted, when using the AppImage, Musescore picks XWayland by default. I don't know how to force the AppImage to try using Wayland natively.