Comment 54 for bug 1301125

Same issue in 16.04.1 LTS, the laptop is Asus Zenbook UX32VD. Black screen, cursor moving.

To avoid restarting and losing all unsaved data, I did the following:
1. Switch to TTY1 (Ctrl+Alt+F1)
2. Log in
3. Kill compiz process:
sudo kill -9 `pidof compiz`
4. Switch back to TTY7 (Ctrl+Alt+F7)

All the graphics reappeared, didn't have to restart.

From what I understand, there is no solid solution here and it's probably related to video drivers. I switched to proprietary nvidia drivers yesterday, probably it was the reason. Or maybe it was related to the leftovers from Xfce which I also installed yesterday and then removed (and it didn't seem to go away that easily).