Please try removing all PPAs from the system (using ppa-purge) and see if that solves the problem.
** Package changed: xorg (Ubuntu) => xserver-xorg-video-amdgpu (Ubuntu) ** Package changed: xserver-xorg-video-amdgpu (Ubuntu) => xorg-server (Ubuntu) ** Changed in: xorg-server (Ubuntu) Status: New => Incomplete ** Changed in: xdiagnose (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/1762127 Title: Ubuntu stuck in loop at boot after upgrade from 17.10 to 18.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xdiagnose/+bug/1762127/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs