When I lock my computer, this message appears on a black background:
The screen locker is broken and unlocking is not possible anymore.
In order to unlock switch to a virtual terminal (e.g. Ctrl+Alt+F2), log in and execute the command:
loginctl unlock session 2
Then log out of the virtual session by pressing Ctrl+D, and switch back to the running session (Ctrl+Alt+F1).
So I did what was said and after digging a bit on internet, I ran
/usr/lib/kscreenlocker_greet --testing and here’s the output:
/usr/lib/kscreenlocker_greet: symbol lookup error: /usr/lib/kscreenlocker_greet: undefined symbol: _ZN12LayerShellQt6Window16setDesiredOutputEP7QScreen
How can I fix this?