Very rarely, some component of the Active Roles solution may not be able to connect via FQDN to a resource hosted on a different computer.
There is no DNS entry for this computer, but there is an appropriately-formatted entry in the Windows HOSTS file located at C:\Windows\System32\drivers\etc
A connection by IP Address is successful.
There is an issue with the client-side DNS Reverse Cache on the Active Roles host.
There is a non-printable character in the HOSTS file which is causing a parsing issue.
Open the HOSTS file in an advanced text editor (such as Notepad++) and remove any non-printable characters which are present.