One of my RDS clients has a pretty robust server farm 2012R2, 4 RDSH servers.
Every once in a while for no apparent reason (have not grabbed logs yet) one of the servers will have trouble reconnecting sessions.
In other words, not the whole farm and never the same server. They use UPD, and after disconnecting the message on reconnect is (and i'm parapfrasing a user as i have not witnessed it) "Windows cannot load profile" and i'm forced to log that session off from the console, they attempt a new login and it works.
Anyone seen this before?