Comment 19 worked for me after reboot on 14.04. The error happened in relation to manual a password reset I did (replaced shadow and passwd with a backup).
https://bugs.launchpad.net/ubuntu/+source/policykit-desktop- privileges/+bug/1240336/comments/19 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1240336 Title: Not authorized to perform operation / Unable to determine the session we are in: No session for pid To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/1240336/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs