The certificate that you have selected for Secure Sockets Layer (SSL) encryption cannot be used due to possible problems ...

The certificate that you have selected for Secure Sockets Layer (SSL) encryption cannot be used due to possible problems with Internet Information Services (IIS). To resolve this issue, troubleshoot and resolve any problems with IIS, and then use Remote Desktop Gateway Manager to select a certificate. For more information, see Obtain a Certificate for the RD Gateway Server in the Remote Desktop Gateway Manager Help.