GDM display manager fails to display login

While booting your Ubuntu machine, go to console by pressing CTRL+ALT+F2 and login with your credentials and try installing lightdm.

sudo apt-get install lightdm

It will ask you which Desktop manager you want to make default, select lightdm and proceed with the installation.

logout and log back in the graphical mode by pressing CTRL+ALT+F7.

It should work fine this time. :)

First press Ctrl + Alt + F2 then login into your account. Then install lightdm as sudo apt-get install lightdm then set lightdm as default by writing sudo dpkg-reconfigure lightdm Then restart the system and voilà! Everything seems to be running perfectly!