panel and desktop broken

[Rex Dieter]

Glenn Holmer wrote:

> From time to time, I've seen that the panel, while it appears, becomes
> unresponsive (right- or left-click does nothing). When this happens, the
> desktop (right-click) also becomes non-responsive.
> 
> Normally, I've been able to recover from this by dropping to console and
> issuing "systemctl restart sddm", but this morning even that doesn't work.
> 
> Anybody else seen this? Know of a workaround or fix?

It's a not uncommon problem of plasmashell process getting stuck and 
deadlocked (often due to some as-yet-unexplained interaction between libxcb 
and video drivers).

the easiest workaround is to restart the plasmashell process:

ALT-F2(krunner): killall plasmashell
(wait a few moments)
ALT-F2(krunner): plasmashell