Created attachment 105494 [details] screenshot of settings windows Windows for the folder view settings and taskbar settings windows are empty. The Plasmashell background is visible inside the window borders.
This bug happens occasionally and I've not managed to reproduce it.
Anything in stdout of plasmashell? Is plasma frozen at this point? (just mouse over a taskbar and see if it highlights)
Plasma continues to work. I've no debug info available unf. It's a bug I've been seeing off and on for at least half a year. After some time of regular use, when trying again, the windows do work well. The windows are transparent. If they are before another window, you can see the content of that window, not just the background of plasma.
Are you able to reproduce this in Plasma 5.17?
In the past I did not find a way to reproduce this issue which happened occasionally. I've not experienced the issue for a long time. I'm still using X11 but have upgraded tot plasma 5.16.
Thanks! Let's call it fixed.