I believe this is because you've installed unity on a Xubuntu system, and then during the upgrade process unity is selected for removal but it is on the blacklist so the upgrade fails.
** Changed in: ubuntu-release-upgrader (Ubuntu) Importance: Undecided => Low -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1216187 Title: unity blocks saucy upgrade To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1216187/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
