Unlike Windows users, Microsoft’s Remote Desktop Connection Client for the Mac requires the purchase of a license (a TS CAL) for the Mac user to connect to a Windows Server. Without one, a temporary license (90 days) will be assigned.

Unfortunately, whether you have a proper TS CAL or not, the license information on the Mac needs to be reset from time to time. And in the first version of Microsoft’s client for OS X, this could be done easily by removing the contents of the folder:

/Users/Shared/Microsoft/RDC Crucial Server Information/

This process is detailed in Microsoft’s Knowledge Base article, 187614 (link)

When the old licensing information is removed, the Remote Desktop Connection client software will request a new one. Simple as that.

BUT, with the 2.0 release of the RDC Client, something broke and removing the licenses from a Mac client no longer worked. So that meant continuing to use the, older, buggier 1.0 release OR … well, there is no “or” because the client would just stop working with the error message, “You were disconnected from the Windows-based computer because of problems during the licensing protocol.”

So what to do?

Well, it turns out that – for me anyway – all I needed to do was remove the client license as before, but then first run the 1.0 client to connect to the server. After the 1.0 client established the connection and set up the new license, the 2.0 client would continue working again. If you try to run the 2.0 client first, the connection will fail and you’ll need to reset the license once again.

The downfall to this solution is that I need to keep the older client installed just for the odd occasion that I need to reset the license. The good news is that this process fixes, the less buggy 2.0 client too!

Republished from ESC!Webs Blogitorials, July 2009