Note that this will reset some stuff like the favorites in the startmenu.
Browse to ~/.local/share/kactivitymanagerd/resources/
and delete the files there but keep the backup folders. Afterwards logout and back in or reboot.
See Monit.
There's a problem being unable to change resolution from 1152x864
to anything else. The workaround is to disable the KScreen 2
background service in System Settings
- Startup and Shutdown
- Background Services
.