KDE: The Window Switcher installation is broken, resources are missing.

So I was highly displeased with the standard Breeze task switcher, and thought I’d get a few new ones by clicking the star icon next to the drop-down menu where you select the task switcher. My recommendation is “Grid”. Trying to use Grid, all I get is this error message:

The Window Switcher installation is broken, resources are missing.
Contact your distribution about this.

Hrm. So then I Google and look at code, waste time trying silly things, just to postpone this problem for another weekend. Well, it’s the next weekend now, and just when I’m about to dive back into the code… I restart X (i.e. re-login), and when I try to bring the message up one more time… It doesn’t appear anymore, and Grid and all the others are working! I try installing one more, and sure enough, it didn’t work, but one more re-login and tada. So the answer to this problem might be: restart your KDE session.

It’s still a bug though. But unfortunately I’m no longer interested in looking into this bug now. :(