While going through my compiz settings, I noticed, that windows decarator is off, and I clicked to turn it on - then clicked yes, before I've read that this will turn off unity.
I tried reenabling it using steps like here:
- Unity doesn't load, no Launcher, no Dash appears
and some others, but this doesn't help.
Unity supported command confirms, that it is supported on my machine. My system is Ubuntu 14.04. Currently I can see that Unity is enabled in ccsm settings (and decorator disabled), but I have no launcher, no upper bar, no side bar, no windows title bar, nothing. Just the desktop. Of course I tried restaring my computer, pluging it off and on again, etc ;)