I have enabled the cube rotation effect for switching desktop. I am seeing a horrible black square that appears when the effect starts and disappear afterwards. The square doesn't correspond to any visible window, it just appears there. Killing plasmashell makes the problem go away (other artifacts appear, but they are possibly other bugs?). Reproducible: Always
Created attachment 99577 [details] Snapshot of the problem.
see bug #361511 but it's a dupe of bug #361516 (and in plasmashell) *** This bug has been marked as a duplicate of bug 361516 ***