I just got hit by this as well. The bug also triggered an Apport dialog, which (IMHO erroneously) pointed to https://bugs.launchpad.net/ubuntu/+source/software- properties/+bug/1167314.
I guess the action linked from the software-properties-gtk "Restart..." button ought to be configurable by a packaged setting. For XFCE, it looks (by quick googling) like "xfce4-session-logout --reboot" would be a suitable value for XUbuntu. $ apt-cache policy software-properties-gtk software-properties-gtk: Installed: 0.92.37.3 Candidate: 0.92.37.3 Version table: *** 0.92.37.3 0 500 http://fi.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages 100 /var/lib/dpkg/status 0.92.36 0 $ grep -rF gnome-session-quit /usr/lib/python3/dist-packages/softwareproperties/gtk Binary file /usr/lib/python3/dist-packages/softwareproperties/gtk/__pycache__/SoftwarePropertiesGtk.cpython-34.pyc matches /usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py: subprocess.call(['gnome-session-quit', '--reboot']) 500 http://fi.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages $ lsb_release -rd Description: Ubuntu 14.04.2 LTS Release: 14.04 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1429185 Title: Restart button in Additional Drivers does not restart Xubuntu To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/1429185/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs