When doing an update on the web-gui there is an error message about a repo problem.
Seems there are no pakages available for 16.1 any more.
16.1 is very old. I'm not sure there is a direct upgrade path? I think your best bet would be to make a config backup and restore it on a new install. One of the devs may have another way to manually update the repos to potentially allow you to upgrade but unless it can skip packages we're talking years of versions that have come and gone.