At our sight we have TS running. Clients cannot only log onto the TS is they are a member of the Admin group. Otherwise they get a message saying that the local policy osf this system doesnt allow you to log on interactively.
I have verified that the Domain users and the Everyone group has permission to log on locally and to access from the network. Also verified that they are not a member of any group that cannot. I cannot see what else it could be?