@jessehouwing's comment it was the solution for me. I deleted the entire contents of this folder: %AppData%..\Local\Microsoft\VisualStudio\14.0\ComponentModelCache (you can delete it herself). And it works great. Thanks to X and all .. TIP: for delete form PowerShell type: Remove-Item -Recurse -Force ($env:APPDATA + "\..\Local\Microsoft\VisualStudio\14.0\ComponentModelCache") ...
tfs,build,team-build,ctp,tfs2015
After downloading the latest version of the VSoAgent.zip file the problem went away. It seems to have been fixed in a newer release of the Agent.