W2012R2 RDS: The number of connections to this computer is limited and all connections are in use right now

Question

Recently, a W2012R2 RDS I am managing has started balking at incoming RDP connections with the following message to the users:

The number of connections to this computer is limited and all connections are in use right now. Try connecting later or contact your system administrator.

Articles regarding this message are few, far between and rarely related to RDS, so I turn to you fine people in hope that someone has a good solution to this issue. In an attempt to circumvent the problem, additional RDP ports have been opened, and it seems to have helped some, but it is not a reliable solution.

Solution

Out of the box, you are limited to two remote access connections and one local console or terminal connection. Opening up 'ports' won't change any of this.

If you bring up task manager and look at the users tab you can see who is currently holding an open session. You can view this information remotely by using 'qwinsta' or 'query session'.

People often open a session then disconnect without logging out and you can use the 'logoff' command to kick them out, if you have admin rights to the machine.

If you want to open more sessions than the two free sessions, Microsoft will be happy to sell you 'terminal services' licenses.

The message you are seeing is simply telling you that all that you are currently entitled to are currently in use.

Comments

[Bjørn H. Sandvik]

Thank you for your response! The server is already fully licensed as an RDS/Terminal Server with 100 per-user licenses installed with several still to spare. It has been running for years without issue until just 3ish months ago. Currently, only 13 users are connected (one 'Disconnected'), so I feel the issue must be elsewhere.