ok, so I tried to install a buildAgent on a different machine (not the server)
and deactivated the buildAgent on the server.
Now it says "no compatible agent" Incompatible runner: 'Ant'
I have no clue what to do or where to look for what to do. Getting started & faq gives no information.
Search in support forum hints to that there might be a problem with a firewall, but instead of continued trial and error it would be nice to get some more information.