I seem to have found a solution. Install polkit, in my case sudo apt install lxpolkit
And then, it may be useful to check the Default applications in Menu -> Preferences -> Default applications for LXSession , select Core Applications , and make sure 'Polkit Agent' is set to lxpolkit. Is it possible that in the default installation of ubuntu, the polkit package is not being installed by default? -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1734095 Title: After upgrade to ubuntu 17.10 Software & Updates not showing authorization popup [gnome-shell[N]: pushModal: invocation of begin_modal failed] To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/1734095/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
