We have a customer who is using Windows Server 2012 R2 with the RDS role installed (Hyper-V client) and there are about 15 users that access the server at any given time. Last week we updated some accounting software and installed a few Windows security updates on the server and now there are 2 users that have an issue trying to login from their Thin Clients. They just get an error saying wrong username or password. The only way we have been able to fix the issue is to login to the RDS server using our administrator account (either thought the Hyper-V console or remotely) and then to open an RDP session to the RDS server and login using the user's normal account. Once we login as the user, we just log off and then they can login fine from their Thin Client. The 2 affected users always log off at the end of the day so it's not a hung RDP session.