After some research, I discovered that the reason for this undesired behavior was not installation of gnome-shell, but rather the "login automatically" option, in combination with having my home folder encrypted. Once I enabled the "login automatically" option, the undesired behaviour (being unable to halt etc.) started.
By the way, the system should not let me enable the "login automatically" option as long as my home folder is encrypted (just as it does not let one have both options during installation), since this defeats the purpose of having one's home folder encrypted. ** Changed in: gnome-shell (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/874881 Title: installing gnome shell makes system unable to halt/reboot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/874881/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs