This was the solution for me as well: sudo pam-auth-update --force Beware that it does change files in pam.d, so if you have a heavily customized pam configuration, prepare to be able to track the changes done, and fix things afterward.
-- You received this bug notification because you are a member of Desktop Packages, 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 Status in “gdm” package in Ubuntu: Confirmed Status in “lightdm” package in Ubuntu: Confirmed Status in “lxdm” package in Ubuntu: Confirmed Status in “policykit-desktop-privileges” package in Ubuntu: Confirmed Bug description: After a new install of 64 bit Ubuntu 13.10 on my second partition, I used dpkg to reinstall all the same packages I had on my 32 bit 13.04 partition. I copied all my home directory files over and updated all the packages. I now find that I don't have permissions to change the network settings; I can't mount my other hard drive or any USB stick using nautilus, or (udisks without using sudo)' I can't run synaptic by clicking on the GUI (I have to go to a terminal and sudo synaptic); etc. I can't find any documentation on the configuration of policykit-desktop-privileges, so I'm filing this bug. For me it appears to be totally broken. Maybe someone can help me out. Thanks, Rob ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: policykit-desktop-privileges 0.16 ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3 Uname: Linux 3.11.0-12-generic x86_64 ApportVersion: 2.12.5-0ubuntu2 Architecture: amd64 Date: Tue Oct 15 20:20:55 2013 InstallationDate: Installed on 2013-10-09 (7 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Beta amd64 (20131008) MarkForUpload: True PackageArchitecture: all ProcEnviron: LANGUAGE=en_US TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: policykit-desktop-privileges UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/1240336/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp