Unable to login after update

[Linneo]

Hello everyone.
I've made my first install of Sabayon.
On first run I've updated with Rigo (452 updates).
After rebooting, I was unable to login at login screen. The screen looks normal, but after selecting my user and typing my password, the Start Session button is not responding and nothing happens if I press enter.
So I formated and made a fresh reinstall.
Loged in with no problem. But again, after update and reboot, login screen is not working. This time I can't even type my password.

Does anybody know what is going wrong with the update?
Thanks.

[dunsurfin]

You will need to give some more information such as which version of Sabayon and what hardware you are using.

[life-on-mars]

Did you run equo deptest && equo libtest after your upgrade?
Can you still login on the console?

Did you try an alternative Display Manager?

[papilello]

I' having the same problem with my MATE desktop.
Sometime it happens that i can login, but after a short time the system crashes and I'm back to the login screen.
Most of the times I'm simply unable to login.
Can you show us the content of your .xsession-errors file?