It looks like an update was installed on our server which has “broken” our RDP access.
The server are physical servers so how can we resolve the issue as we can't RDP the server. The servers are Windows 2012 R2 servers
There's way to fix this issue as describe in KB4093492.
Basically have both client and server fully patch, and if that's not possible update the client computer's registry with this value:
Registry path : HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters Value : AllowEncryptionOracle Date type : DWORD
If you want a quick fix and you are within secured intranet, you can use this on the server side:
Logon to Windows Server as a local administrator and open Server Manager from the desktop Task Bar or Start Screen.
In the left pane of Server Manager, click Local Server. Wait a few seconds for the information about the local server to update in the right pane. In the Properties section of the right pane you should see the status of Remote Desktop, which is disabled by default.