TSplus Remote Access does not support more than 15 concurrent sessions on Windows Server 2016.
This does not mean it cannot work beyond this limit, but we cannot guarantee or ensure it will.
The issue is due to the specific behavior of the Windows Shell (explorer.exe) in this version of Windows.
This component sometimes fails to handle additional sessions correctly.
To improve compatibility, we recommend forcing the use of the alternative shell, WinXshell, in the Advanced Settings.
This workaround may help in some cases.
However, depending on the client used and the internal handling of the user shell and desktop, this limitation is often impossible to overcome.
So it is recommended to use Windows Server 2019 and 2022 instead.
And it will ensure better security and more support time from Microsoft.
This article is related to our pre-requisites documentation :