Looking further, I attempted to boot into low-graphics mode. I get the message:
"Your screen, graphics card, and input device settings could not be detected correctly. You will need to configure these yourself" -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/752997 Title: [regression] Xorg freeze on login screen. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
