I think I found the cause. I accidentally forgot to install diodon clipboard manager and machine logout instantly.
Khurshid, can you check if you have didon installed and if removing it helps? -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-session in Ubuntu. https://bugs.launchpad.net/bugs/1547603 Title: Logout fails (Unity7,Ubuntu-Gnome, Xenial) Status in gnome-session package in Ubuntu: Confirmed Bug description: On my machine logout takes too long time and eventually fails. Syslog or /var/log/lightdm doesn't give something very useful. From syslog only error I find is: Feb 19 22:15:57 Saturnica gnome-session[1162]: gnome-session-binary[1162]: GLib-GObject-CRITICAL: g_object_unref: assertion 'G_IS_OBJECT (object)' failed Feb 19 22:15:57 Saturnica gnome-session-binary[1162]: GLib-GObject-CRITICAL: g_object_unref: assertion 'G_IS_OBJECT (object)' failed...... I can reproduce this in both Gnome-shell and Unity7. I attaching the part of the syslog. If more information is required I will provide it. Gnome-session: 3.18.1.2-1ubuntu1 Systemd: 229-4ubuntu4 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/1547603/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

