NOTE: I have opened another post on this issue earlier but had to open a new one as a new problem has arisen and the original solution no longer works: https://social.technet.microsoft.com/Forums/en-US/18a05b7e-ac2b-41e3-a8ef-c3b83ca3bc78/remote-desktop-services-server-authentication-certificate-problem?forum=winserverTS
We have a virtual server running Windows Server 2012 and several workstations on Windows 10. Employees regularly need access to the virtual server - remotely connecting via the workstations. However, recently they are running into a problem; when they try to remotely connect to the server, it comes up with the error:
The connection has been terminated because an unexpected server authentication certificate was received from the remote computer.
This used to only occur sporadically but it is now a permanent issue for them and for us. I have taken a look at other solutions to this problem
- Replacing mstsc.exe and mstscax.dll with ones from Windows 10 build 1511 - the workstations are running Build 1909 and have never ran build 1511.
- Registry - the only registry options in HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client are (Default) and PinConnectionBar - no RDGClientTransport
- "Connect and don't warn me" - option is stuck on "warn me" with no option to change it
- Services - both the Remote Desktop Services and Remote Desktop Services UserMode Port Redirector are up and running.
- Setting fSingleSessionPerUser to 0 - doesn't work anymore
- Changing the GPO setting to limit the max number of connections to 999999 (unlimited) - doesn't work anymore
I imagine this is now an issue with the certificate of the machine, not an issue with the remote desktop service itself. I can't seem to figure out what issue specifically it is