• System: 2008 R2 Enterprise w/SP1.

• GPO governs Terminal Services, i.e., all servers are in the same security group and operating under the same GPOs. The server in question is the only one presenting a problem

• GPO governs firewalls, so all these servers have the exact same firewall settings. I've even tried turning the firewall 'Off' on the server in question.

**The symptoms of this problem are, when connecting through RPD (1) instead of asking if you want to disconnect a session, it gives and error message, and (2) if I'm logged in, and then try to login in again from a different system, it doesn't 'take over' my previous session, it gives me the error again.** See image for error.

**If only one, or no other users are connected via RDP, then there is no problem connecting.

Normally, by default, 2008 server allows two RDP sessions. If a third remote session tries to connect, it gets a message stating "Select a user to disconnect so that you may login" and it shows you the two current users, and allows you to disconnect one of their sessions.

I have one server, a clean install of 2008 R2 Enterprise, that returns an error message, "This computer cannot connect to the remote computer" instead of the usual "who do you want to disconnect" message. See second image below.

Test for Events:
I've actively had two logins going, activated a third login and then checked the Event Viewer on this server for any errors or notification, but found nothing (Looked in Application, Security, System, RemoteDesktopServices, TerminalServices-RemoteCOntrolManager) and found no errors or warnings.

Any thoughts on what may be causing the RDP client to get this error instead of the usual 'user disconnect' options?

 

Update: The one difference I've found between the server in question and all other servers is the RDP-Tcp connection version is 7.1, whereas all the other servers run v.6.1. Beyond this I've been able to find no info on the differences of the connection types.

Update: The one difference I've found between the server in question and all other servers is the RDP-Tcp connection version is 7.1, whereas all the other servers run v.6.1. Beyond this I've been able to find no info on the differences of the connection types.

Hi Zpunky,

I think you reach maximum number of connection allow to use RD clients. you can change that settings under RDP-TCP. go to network adapter and change the setting according to your requirement. 

Regards,

La

Hi Zpunky,

I think you reach maximum number of connection allow to use RD clients. you can change that settings under RDP-TCP. go to network adapter and change the setting according to your requirement. 

Regards,

La

Thanks Linda, but that's not the issue; I'm aware of the default 2 user limit. The issue is *on this server* when 2 people are already connected and a 3rd tries to connect, instead of receiving a dialog box asking if they want to disconnect one of the other sessions, they get an error message that they are unable to connect. What they should see is this image.

Chris

• Marked as answer by Boo_MonstersIncMicrosoft contingent staff, Moderator Thursday, February 02, 2012 5:41 AM

Thanks Linda, but that's not the issue; I'm aware of the default 2 user limit. The issue is *on this server* when 2 people are already connected and a 3rd tries to connect, instead of receiving a dialog box asking if they want to disconnect one of the other sessions, they get an error message that they are unable to connect. What they should see is this image.

Chris

• Marked as answer by Boo_MonstersIncMicrosoft contingent staff, Moderator Thursday, February 02, 2012 5:41 AM

Incorrect registry key setting that specified 0x00000002 (2) instead of 0xffffffff (4294967295).

Set: HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

MaxInstanceCount    REG_DWORD  to  0xffffffff (Hex value ffffffff, eight f's), and reboot.

• Marked as answer by Zpunky Wednesday, February 01, 2012 12:31 AM

Incorrect registry key setting that specified 0x00000002 (2) instead of 0xffffffff (4294967295).

Set: HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

MaxInstanceCount    REG_DWORD  to  0xffffffff (Hex value ffffffff, eight f's), and reboot.

• Marked as answer by Zpunky Wednesday, February 01, 2012 12:31 AM

Hi Zpunky,

 

Thank you for sharing your experience and the solution which will help others. Appreciated.

 

 

Thanks

ZHANG

Hi Zpunky,

 

Thank you for sharing your experience and the solution which will help others. Appreciated.

 

 

Thanks

ZHANG

I am looking for answer for the same problem. There is no actual answer in this thread. It should be re-opened. There is no problem connecting to existing session if it is explicitly disconnected. But I am getting the error above if the server thinks that session is still connected.

I am looking for answer for the same problem. There is no actual answer in this thread. It should be re-opened. There is no problem connecting to existing session if it is explicitly disconnected. But I am getting the error above if the server thinks that session is still connected.

This registry fix resolved my server issue. Now we are able to see the two users
already logged in dialog box. I want to say that I have not rebooted the server
as it was live in production but i can see the registry fix the issue without
rebooting the server.<o:p></o:p>

Thank you
very much :) really appreciate.<o:p></o:p>

Thanks for this Zpunky, this works without a reboot as well.

Thanks for this Zpunky, this works without a reboot as well.