vsts sourcecontrol provider does not work


With svn I have no problem, but when I specify vsts as sourcecontrol provider I get the following error:
[CCNet Server:ERROR] Exception:
Unable to instantiate CruiseControl projects from configuration document.
Configuration document is likely missing Xml nodes required for properly populating CruiseControl configuration.
Type with NetReflector name "vsts" does not exist. The name may be incorrect or the assembly containing the type might
not be loaded.
Can be solved by starting ccnet.exe with working directory the directory where ccnet.exe lives.