2 machines with Ubuntu Mate 16.04, with nearly identical features.
On one of them the icons of running apps/programs suddenly don’t appear in the panel any more. Just gone.
If I minimize something, it’s gone - nowhere to be found. It’s still running but I can’t find it again.
An internet search didn’t turn up anything even similar. Any ideas?
(Opps, found this other question after I posted - my post should go there maybe - how?)