The mirror you are using doesn't seem to mirror the Trusty release of Ubuntu.
http://ftp.ncnu.edu.tw/Linux/ubuntu/ubuntu/dists/ I recommend switching mirrors using the tool software-properties-gtk and then trying the upgrade again. ** Changed in: update-manager (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/1404796 Title: Ubuntu would not update To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1404796/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
