I created a new launcher in menulibre. After saving, menulibre crashed into fallback mode. Restarting my computer does not help. The menus are currupted.
See the error message here: https://i.sstatic.net/sYW0M.png
I found out, that the menus are located under:
/home/<USER>/.config/menus
I found a hint that it might work to delete the menus folder:
https://forums.linuxmint.com/viewtopic.php?t=353581
Is it safe to do that and will it restore my menus?