Comment # 10 on bug 1185271 from Christopher Yeleighton

(In reply to Fabian Vogt from comment #9)
> That's the first time I've heard of this issue. I fixed some issues related
> to SystemSettingsExternalApp in Plasma 5.21, but never came across this.
> 
> The error means that it tried to load the module as KCM library, but it
> should never reach that code because of X-KDE-ServiceTypes.
> 
> Did you just open systemsettings and click on the YaST icon? Is it using the
> icons view or the sidebar view?

icons

 Does it still happen after running
> "kbuildsycoca5 --noincremental"?

I have unpatched the file and it works now without the library declaration.  As
I said, it comes up only from time to time.  But it is annoying enough to
report it.