I've got a strange security/licensing issue with my new server 2012 RDS domain.
Servers keep randomly dropping out of the RDS pool I created which includes 5 RDS Session hosts servers, a connection broker and a licensing server. This group has been created on each server, and all include all of the servers including the local server itself.
When there is a server missing from the group, you are unable to connect to Remote Desktop Services through server manager unless you add it back in.
Biggest problem however, is I keep getting "Because of a security error the client could not connect to the remote computer..." when RDP from an XP Embedded dumb terminal. It just seems to suddenly happen on each server with no clear pattern- although seems to be more often triggered by server restarts. Once I server starts giving the error, seems to be no clear way of reversing whatever caused the problem, literally been having to rebuild each server.
It's not network level authentication, and RDS licensing diagnoser on each server shows no issues.. Also finding no useful information in event viewer.
Only issue i've noticed is the licensing server is issuing some RDS Cals, and some Temp RDS cals. Some PCs have been issued both. It shows 111 of 130 licenses available, yet is issuing both temp and regular RDS CALS.