Trying to upgrade to 16.04.
Tried following How to install software or upgrade from an old unsupported release? as best as I can, but soon ran into trouble by getting lots of 404 errors when I tried to replace the repositories with old-repositories (GUI Method).
Also Vivid seems to not be listed in the old-repositories directory http://old-releases.ubuntu.com/ubuntu/dists/, which seems to me to be the issue, why would it now be listed?
Any help would be much appreciated.