If you are runnign a new Windows server, havent' installed Remote Desktop Gateway, you don't have Remote Desktop Services availalbe in your Server Manager, or anything similar, run this command in an elevated command prompt and all will be well:
wmic /namespace:\\root\cimv2\TerminalServices PATH Win32_TSGeneralSetting Set SSLCertificateSHA1Hash="THUMBPRINT"
Use this link for the full documentation:
https://technet.microsoft.com/en-us/library/dd320345(v=ws.10).aspxUse this link for the full documentation:
https://technet.microsoft.com/en-us/library/dn781533(v=ws.11).aspx