> The system flashes a very momentary prompt to login as a single user without a GUI, but then the screen goes black and the system is hung.
That sounds like the command actually worked, but stopping lightdm and thus the graphics driver breaks the state of the graphics card. Does changing VTs with Ctrl-Alt-F2 work? If not, please check if you can still log into the system with ssh (I suppose that works), and capture "sudo journalctl -b > /tmp/journal.txt" and "systemctl status > /tmp/status.txt" and attach the files here. Also, which graphics driver/card are you using? Please don't file bugs direectly in Launchpad, use "ubuntu-bug" for this (this will automatically attach information about your hardware). > The glaring difference I noticed is that in the multi-user.target unit file, AllowIsolate and CanIsolate is set to yes in the other Linux systems, but to no in Ubuntu. Ubuntu does not modify the upstream unit, and it does have AllowIsolate=yes. "CanIsolate" does not exist. ** Changed in: systemd (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1603151 Title: systemctl isolate anyname.target not working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1603151/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs