We have a Windows 10 Pro user who is trying to access his RDS account on a Windows Server 2012 RDS system. He VPN's into the firewall and has a valid network address. Then he opens the RDS app and types in the server IP address, his user credentials and clicks Connect. He gets this error "Your computer could not connect to another console session on the remote computer because you already have a console session in progress."
Others in his company (also running Windows 10 Pro) can connect to the SAME VPN and, using the SAME credentials and server IP address, CAN connect to this server and establish an RDS console session. It is ONLY this one machine that is having an issue.
I have never encountered this before. They have SIGNED OUT of the session, closing all connections, yet this one computer CANNOT connect.
How can I troubleshoot this to get him connected to the RDS session?