Desktop gets stuck

Description: the existing windows cannot be moved or closed. New windows cannot be created. Or something else is badly wrong with the desktop.

Hitting the Windows key (between Ctrl-Left and Alt-Left) seems to be a cure.

If this is not the helpful, you have to try the following procedures. The first two are harmless, not on Debian-10, in the sense that all applications remain alive and no user input is lost. On Debian-10 you might getted logged-out. The third, reboot, is the ultimate measure.

• If the keyboard still accepts input, use Alt-F2 to open a command widget and supply 'r <enter>'. This restarts the Gnome shell, the 'desktop'. All applications remain alive; under Debian-10 this is not always the case.

• If the above procedure does not work, use Ctrl-Alt-F3 to open a non-graphical terminal, login as beamline user and issue pkill -3 gnome-shell. This restarts the Gnome shell (desktop). Use Ctrl-Alt-F2 to re-enter the graphics mode. All applications remain alive; under Debian-10 this is not always the case.

• Reboot If the above procedures do not work, use Ctrl-Alt-F3 to open a non-graphical terminal, login as beamline user and issue tango stop and sudo /sbin/shutdown -r now. This reboots the PC. All applications are terminated. Edits may got lost.