This is the first time I've figured out a way to capture this image. Usually it disappears from my screen before I can do that.
This is somehow associated with the KDE hibernation problem I've been fighting with. I preserved this image by taking a screen shot, then pasting it into a Telegram message.
Then I loaded the usual applications into all the workspaces except for my browser, and hibernated the laptop. When I woke up the thing, everything worked perfectly for a change. Including this image, which is still available. (Gonna delete that message now, 'cause I have no intention to send it to anyone.)
Part of this problem involves error messages that I haven't been able to capture because the computer is locked while they're displayed. They have something to do with a Plasma browser connection. I'll run though this again with my browser running, and copy the error message to a notepad manually.