I have a user with a Mac, iPhone, and iPad who was connecting fine to a 2008 R2 RDS server. He used MS RDC client on the Mac and iTap on the phone and tablet.
We recently moved RDS from the 2008 server to a 2012 server. Windows clients are connecting just fine to it. But the Apple user is unable to connect on his Mac or his iPhone. He can still connect on his iPad. I'm leaving the iPhone problem for later as I think that's just a configuration issue since it uses iTap just like the iPad which -is- connecting. I'm concentrating on the Mac.
So far my research has turned up only 2 things. Make sure the RDC client is at 2.1.2 as anything earlier will have problems; or use CoRD, though that application seems to have issues of its own.
I've looked in the event logs on the RDS server and there are no events created at the time he's trying to connect.
When he does try to connect he's getting 2 errors. One says "the server name on the certificate is incorrect" and the other is "you were disconnected from the Windows-based computer because of problems during the licensing protocol."
He was running RDC 2.1.0 and I had him upgrade to 2.1.2 but he gets the same results. Before I tell him to try installing and using CoRD, I thought I'd see if anyone else with a 2012 RDS server has run into this and find out what you did to fix it.
Jonathan