Black screen after login Ubuntu Gnome 16.04

I had just updated to Ubuntu gnome 16.04 from 15.10.

After reboot, I type password and click Login but just show a black screen, the desktop was not loaded.

I just go to the desktop by type Ctrl+Alt+F1, then use command startx.. What was happened with my system ?

The only workaround available to this bug is to download and choose lightdm as the login manager of Ubuntu, rather than the default GDM, I've downloaded and installed it from Synaptic with ease and chose it as default by running the command : sudo dpkg-reconfigure gdm, once you see this message hit Enter.

Then you see this window, choose lightdm and hit enter.

Your selection will be available on the next reboot.

Source and bug details [Here].