session directory active

Hello

I have problem to add session host server to a collection by Windows 2012 R2 environment. I can't find any GPO entry for that error. I have a subdomain conzept, if I do add the session host on the Gateway server which is located on ths top level domain, then I can add a session host server, but not when I do it on a subdomain. I can find some blog entry but all refer to Windows 2003.

Any input would be gratful

André

Here some more infos:

Error: The Property session directory active is configured by using Group Policy settings. Use the Group Policy Management Console to configure this property.