can't log in gnome

Hi, I'm on gentoo 3.20 with systemd. From yesterday it's impossible to
log in as user (works good as root), to gdm and shell, in 'normal mode'
with password.
If I set in gdm configuration the automatic access, I can log and work.
I tried to create a new user with the same problem.
I checked, pam, pambase, gdm but nothing seems to be wrong.

Best Regards