Cannot login after upgrade to Linux Mint 19

[ferhue]

HI, I had Linux Mint Mate 18.3 and upgraded to 19. I see the login screen, but after entering the password it turns black and goes back to the login screen.
I am able to login through the terminal (ctrl alt f1).

The log file says connection to X server lost.

Any ideas?

[kukamuumuka]

Boot into Recovery mode, where drop to the root prompt, where run

Code: Select all

mount -o remount,rw /
nmcli dev status
apt-get update
apt-get install --reinstall lightdm mate-desktop
dpkg-reconfigure lightdm
sync
reboot