When Windows Server 2016 installs cumulative updates, termsrv.dll is often replaced by a newer version. This will undo your manual patch or cause RDP Wrapper to stop working until a new configuration file is released for the wrapper.

The file termsrv.dll , located in C:\Windows\System32 , is the library responsible for Remote Desktop Services. By default, non-server editions of Windows (and Server editions without the RDS role configured) allow only active session; if a second user logs in, the first is disconnected. The "patch" involves using a HEX editor or automated script to replace specific byte sequences within this file to remove that internal session limit. How to Apply the Patch (General Process)