Have had a similar issue. When I tried to run "loginctl" I got "Failed to issue method call: Cannot launch daemon, file not found or permissions invalid" and trying to execute polkit-gnome-authentication-agent-1 resulted in "Unable to determine the session we are in: No session for pid ...".
None of the solutions above helped for me. What helped for me was to remove all i386 parts of PAM (which got installed with Skype) similar to https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1295521/comments/15 I then rebooted and got all functionality back. After reinstalling Skype and the libs and rebooting everything is still working fine. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm in 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 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
