Windows Server 2008 R2 Web Access

I recently set up a Terminal Services server with TS Web Access. I  have made all of the configurations and e activated the server with 20 user CAL.When iam  trying to access the published application i get the notorious error message " to logon to this computer you must be granted allow logon through ......I have added the users to remote Desktop users aswell as to the published application.Any help would  be appreciated.