Strange black square on desktop

English Install/Boot/Login
1

This morning when I booted up my desktop PC I find that I have a small black square about 1cm x 1cm at the top lefthand corner of the screen, nothing displays in this area and it looks like whatever is displaying on the desktop is behind this area. Obviously something has crashed but I have no idea what it might be, I was not watching when it booted so I dont know if there was any fleeting message and certainly no message which had to be acknowledged. This strange black square is there after a power down and boot up again.

I did check ksysguard and kwin and sddm seem to be running OK which were the things I though might have caused it. Any ideas please?

Stuart

2

Normally there would be the desktop’s toolbox icon in the upper-left corner, and this is about 1x1cm in size.

Maybe try to delete the Plasma theme cache files ~/.cache/plasma*.

Also try whether you see the same problem on a fresh user account.

Might also be a graphics driver issue though, maybe disabling compositing could help.

3

I’ve already moved that to the RH side of my desktop. A subsequent reboot later in the ay and it has not re-appeared so will wait and see before I try anything for now.

Stuart