Recently, I got the below message when trying to MSTSC into a RDP targeting a Windows 7 machine having multiple NICs.
Remote Desktop Connection
Your computer could not connect to another console session on the remote computer because you already have a console session in progress.
I was connecting from a WAN. The Windows 7 machine is connected on two different subnets through port forwarding.
The above message was only on one on one WAN connection. When I tried the other, I could connect immediately. After that, I could connect through the other WAN connection as well.
I’m not sure what caused it, but I suspect the port forwarding, though that has worked in the past and now works without any change.
Still a couple of links, just in case it happens again: