I got around this problem by adding the line "deb http://packages.linuxmint.com/ qiana main upstream import" to /etc/apt/sources.list and then attempting the upgrade. This worked for me, but I would strongly recommend backing up your system before trying it in case of disaster.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1279762 Title: upgrade to 14.04 from 13.10 or 12.04 failed - cinnamon fails to upgrade To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cinnamon/+bug/1279762/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs