Unity Top Bar and Launcher disappeared Feb 24/2018 [duplicate]
Solution 1:
Update: Yesterday I tried advice from WinEunuuchs2Unix answer in ubuntu-menu-and-launcher-not-showing-after-2-16-2018-update and it fixed the problem in my case.
rm -rf ~/.config/compiz-1/compizconfig/*
I have tried to remove it before, but nothing changed. And just after mesa downgrade, and then removing compiz config files Unity panels come back to their usual places. But I still can't understand what was the main cause of crashing.