The self-signed certificate to be used for Secure Sockets Layer (SSL) encryption could not be created. To resolve this issue, ...

The self-signed certificate to be used for Secure Sockets Layer (SSL) encryption could not be created. To resolve this issue, use Remote Desktop Gateway Manager to either create the self-signed certificate or to select another certificate. For more information, see Obtain a Certificate for the RD Gateway Server in the Remote Desktop Gateway Manager Help.