I installed Windows Server 2012 and was able to connect 2 remote desktop users as expected. When the 3rd tried to connect it said you had to kick off one of the two simultaneous users currently on.
So I purchased a Per-User 5 license Open CAL and applied it. It is listed correctly as installed in the Remote Desktop Licensing Manager. Total licenses 5, available 5, everything looks great.
However, trying to connect a 3rd user via Remote Desktop to this server still gives the same error. I have done this before in Windows Server 2008 without a problem. Any ideas? I have the Remote Desktop Service role installed.
Not sure why the downvote for the question, but here's what worked for me:
Add the Remote Desktop Session Host role.
Apparently that has to be there for it to work properly.