We installed the newest TFS Server (TFS 2018 Update 2) which should run xaml builds.
After the update, we started our agent, but our xaml-controller is still offline and I d
Thanks @PatrickLu-MSFT!! through your help, we found a workaround.
Now we use one server for the Source Control etc. (TFS 2018) and another server only for the xaml-app-controller with TFS 2015.
So we can build our projects, and have time to create new build definitions.