I just did a fresh install of Ubuntu 16.04 that I set to log in automatically. When it loads up all I get is the desktop wall paper but not top panel or unity side bar. Previously I was using Ubuntu 16.04 Mate edition and everything worked great. I read this question Ubuntu 16.04 unity desktop environment doesn't load after fresh install but I could not get to a tty screen like the poster in that thread. When I did Ctrl+Alt+F1 all I would get is a blank screen. I've tried switching monitor inputs and going from my nvidia card to the onboard graphics but nothing seems to work. I'm just going to switch back to Mate for now but I would really want to check out what's new in Unity. Thanks for any and all help!
Fix compiz problem :
sudo rm -fr ~/.cache/compizconfig-1 sudo rm -fr ~/.compiz
Then try this if your session not loading :
sudo rm -fr ~/.Xauthority sudo rm -fr ~/.config/autostart
sudo apt-get install --reinstall ubuntu-desktop unity compizconfig-settings-manager upstart
Finally clear the Unity Desktop :
sudo dconf reset -f /org/compiz/ setsid unity
This is how I fixed my problem hope it could be helpful to you.