Estou usando o Xubuntu 14.04. O login foi bem-sucedido na primeira vez após a inicialização, mas quando uso o usuário comutador para efetuar login como usuário normal (não raiz ou sessão de convidado), ele pisca e depois retorna para a interface de login.
Eu li perguntas semelhantes no Ask Ubuntu, mas ainda não consigo resolver o problema.
auth.log para o login pela primeira vez
Sep 1 00:17:01 rpdzkj-ubuntu3 CRON[1129]: pam_unix(cron:account): account root has password changed in future
Sep 1 00:17:01 rpdzkj-ubuntu3 CRON[1129]: pam_unix(cron:session): session opened for user root by (uid=0)
Sep 1 00:17:01 rpdzkj-ubuntu3 CRON[1129]: pam_unix(cron:session): session closed for user root
Sep 1 00:23:12 rpdzkj-ubuntu3 lightdm: pam_unix(lightdm:account): account rpdzkj has password changed in future
Sep 1 00:23:12 rpdzkj-ubuntu3 lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm
Sep 1 00:23:12 rpdzkj-ubuntu3 lightdm: pam_unix(lightdm:session): session opened for user rpdzkj by (uid=0)
Sep 1 00:23:12 rpdzkj-ubuntu3 systemd-logind[392]: New session c3 of user rpdzkj.
Sep 1 00:23:12 rpdzkj-ubuntu3 systemd-logind[392]: Linked /tmp/.X11-unix/X0 to /run/user/1000/X11-display.
Sep 1 00:23:14 rpdzkj-ubuntu3 gnome-keyring-daemon[1147]: couldn't set environment variable in session: The name org.gnome.SessionManager was not provided by any .service files
Sep 1 00:23:15 rpdzkj-ubuntu3 polkitd(authority=local): Registered Authentication Agent for unix-session:c3 (system bus name :1.52 [/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1], object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
troca de usuário ou após um certo tempo o Xubuntu permanece parado, o que entrará na interface de login.
Aqui está a segunda vez ou mais tarde auth.log
Sep 1 00:25:51 rpdzkj-ubuntu3 lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm
Sep 1 00:25:51 rpdzkj-ubuntu3 dbus[302]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.107" (uid=112 pid=1938 comm="/usr/lib/arm-linux-gnueabihf/indicator-bluetooth/i") interface="org.freedesktop.DBus.Properties" member="GetAll" error name="(unset)" requested_reply="0" destination=":1.1" (uid=0 pid=365 comm="/usr/sbin/bluetoothd ")
Sep 1 00:25:51 rpdzkj-ubuntu3 dbus[302]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.107" (uid=112 pid=1938 comm="/usr/lib/arm-linux-gnueabihf/indicator-bluetooth/i") interface="org.bluez.Manager" member="DefaultAdapter" error name="(unset)" requested_reply="0" destination="org.bluez" (uid=0 pid=365 comm="/usr/sbin/bluetoothd ")
Sep 1 00:25:52 rpdzkj-ubuntu3 lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
Sep 1 00:25:52 rpdzkj-ubuntu3 lightdm: PAM adding faulty module: pam_kwallet.so
Sep 1 00:25:52 rpdzkj-ubuntu3 lightdm: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Sep 1 00:25:52 rpdzkj-ubuntu3 systemd-logind[392]: New session c5 of user lightdm.
Sep 1 00:25:53 rpdzkj-ubuntu3 lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
Sep 1 00:25:53 rpdzkj-ubuntu3 lightdm: PAM adding faulty module: pam_kwallet.so
Sep 1 00:25:53 rpdzkj-ubuntu3 lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "rpdzkj"