Thanks for yourt report. The root cause of the issue is the Xorg stack installed from the padoka PPA. Please revert these packages and try to upgrade again.
Don't hesitate to file any bug you may find. ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1769576 Title: not able to upgrade from ubuntu 16.04 to 18 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1769576/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs