Whenever Microsoft releases a security update or cumulative rollup that touches the Remote Desktop component, Windows will overwrite your modified termsrv.dll file with a fresh, unpatched version.
Set to Disabled .
Download TermsrvPatcher. place it in any folder e.g. Right click on TermsrvPacther. ps1, select 'Run with PowerShell' and enjoy Termsrv.dll Patch 10.0.17763.437 #750 - GitHub universal termsrvdll patch windows server 2012 r2 best