Comment 28 for bug 1632322

Just tested and on 16.04 and 17.04 installing xserver-xorg-legacy did nothing. I still get a black screen. What I did was install gnome desktop (gdm3 package), selected the gdm package instead of lightdm in the reconfiguration screen and after rebooting the problem started. The logs say everything is awesome but it's simply not working. If it helps I have the 378.13 Nvidia drivers, an Nvidia GTX 1080, 64GB Ram, Intel 6700k and Ubuntu 16.04 64 on the first test and then 17.04 on the second test. Both with the same issue.