Step1:
Login to a user account.
Step2:
Now open the file /etc/pam.d/gdm3 and comment out the fifth line:
#auth required pam_succeed_if.so user != root quiet_success
Content of: /etc/pam.d/gdm3
#%PAM-1.0 auth requisite pam_nologin.so auth required pam_env.so readenv=1 auth required pam_env.so readenv=1 envfile=/etc/default/locale #auth required pam_succeed_if.so user != root quiet_success @include common-auth auth optional pam_gnome_keyring.so @include common-account session required pam_limits.so @include common-session session optional pam_gnome_keyring.so auto_start @include common-password
Step3:
Reboot.
Last updated: 31 Marzo 2015 by Pierluigi Minati