CA Communication Error when adding an MS CA

Symptom: When adding a Microsoft CA, you may get the error "Communication with the CA has failed, please check the settings before trying again. System error: CCertAdminGetCAProperty: The RPC Server is unavailable". This will be seen when trying to load the templates from the CA

Cause: This is caused if the IP address for the MS CA is used instead of the FQDN.

Solution: 

1. Make sure that the FQDN of the MS CA can be resolved, and that the IP address of the MS CA resolves to the host name.
2. In the "Connection" section of the MS CA setup, use the FQDN instead of the IP address