14.10has reached end of life on Jul 2015; so you need to choose 15.04 for upgrading.
https://wiki.ubuntu.com/Releases ** Summary changed: - impossible to install required package + ubuntu-release-upgrader is not aware about EOL versions ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1492867 Title: ubuntu-release-upgrader is not aware about EOL versions To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1492867/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
