Comment 137 for bug 969489

This bug hit me after an upgrade from 14.04 to 16.04.1. Strangely I was not affected earlier. Maybe a reinstall might fix this issue? Two out of three reboots leads to failsafe X. Sleep command improved the situation but still 50%... Other solutions like restart in rc.local somehow did not work. Maybe systemd is ignoring it or it is executed way to early.
Maybe this bug is related to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1070150 ?

gdm3 currently only comes up with a black screen and a mouse cursor and no error in the logs...
sddm is working fine but the lockscreen locks the terminal permanently and only killing the process on tty1 unlocked it.

Current workaround with a newly created systemd service which starts after the graphical target is completed. (see attached file)

systemctl enable lightdmrestart
systemctl reboot

Currently working without an issue. Hope it helps if someone else is still affected and needs a quick fix.