OSX Mac RDP Clients cannot connect to Terminal Server 2012 because of problems during the licensing protocol

Last month I replaced our old windows server with Windows 2012 Terminal Server.

After the install, I installed Microsoft Remote Desktop 2.1.1 on all of my Apple Mac OSX 10.8 iMacs.

All was working perfectly.

After what I think is 45 days all my Apple Macs suffered the same problem when trying to establish a RDP connection.

See attached Image:
"You were disconnected from the windows-based computer because of problems during the licensing protocol."

If I try connecting from a spare PC using Remote Desktop and the same user credentials I am able to log in fine.

This means the user has permission to log on. The Terminal Server is refusing connections from all my Apple Macs.

If this is really a Licensing Protocol issue, I wonder if the problem is caused by temporary Device CALS expiring?   I am fully licensed with plenty of CAL's, It should be applying device cal's to Apple Macs.

I need help diagnosing the problems here.  Is there a log file I can read on the Terminal Server that tells me exactly why it refuses connections from my Apple Macs?

Is there a way to flush out the device cals or check to see if they are allocated properly to my Apple Macs?

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I believe switching from the MS RDP client to the open source CoRD will fix the problem:

MchallinorAuthor Commented:
Nope,  I've tried CoRD and for some reason It will not connect to my Terminal Server.
CoRD will connect to some of my other Windows Servers,  but just hangs when trying my Terminal Server.
No error message either.

iTap will work but I refuse to spend over £300 to get my Apple Macs working on Terminal Server when I believe the issue with is with Windows Terminal Server 2012.
MchallinorAuthor Commented:
For anyone else searching this problem I can summarize:

The problem circulates around a special folder on the Mac:
/users/Shared/Microsoft/RDC Crucial Server Information

This folder and files are created on first connection to a Terminal Server and most likely contain the Device CAL information for the server.

Some people believe all you have to do is make Everyone read/write access to this folder so the Terminal Server and load new server licensing information.

I have followed all the instructions and deleted the files , re-installed MS RDP.  But nothing I can do will rebuild these folders or allow new information to be received from TS.

There is a UNOFFICIAL release of RDP 2.1.2  -  Be careful as this could be a clever way for some code hacker to gain access to your Terminal Server + key logging.   The risks of having a hacked version of RDP are too high!

There is a common assumption that this is a Microsoft bug in the Mac RDP client.

I think some pressure needs to be put on Microsoft to start debugging this and releasing a new version of RDP.

I have found a very simple work around for now.

1)  Using the a administrator account on the Terminal Server, create a Local User on the Terminal Server with (local) Administrator permissions.

2) From the Mac, Connect to   =  
<server> /console
Where <server> is the address or name of your Terminal Server.

3) If you log in using the local user account you created in step 1, you will be in!

Your users have local admin rights on the Terminal Server.   Be warned!
Only 2 users can log in at a time!

This is the only workaround solution for MS RDP.
Otherwise I'm forced to purchase iTap or Remotix.   CoRD is free but didn't work :(

I'm going to wait a bit longer for Microsoft to release a new version of the RDP client.

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MchallinorAuthor Commented:
Through many hours of trial and error I discovered a workaround solution myself.
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Windows Server 2012

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