Unable to see login screen after upgrading to ubuntu 16.04 LTS

[Krishna_Prasad_Gaj]

Hi, I have recently upgraded from ubuntu 14.04 to 16.04. I can't see the login screen. I can just see a terminal tty1 for logging in. What I have to do to fix this issue?
Thanks in advance.

[ubfan1]

Lots of possible causes, but we need some more information before suggesting anything.
What kind of video hardware do you have?
Were you using any proprietary drivers on your 14.04 ?
Do you have a dual monitor setup?

[cosma-it]

We have a similar problem on Toshiba C55 Laptop.
Used at 14.04 before LightDM tired now to switch to GDM, same problem.
Only when we see the Login Screen is, when we start Ubuntu in "Startup Mode"

Any suggestions?