Problem
If the hosts file is modified on the SPFServer host, and the IP address mapping does not include the fully qualified domain name (and the host on the vault is given as local host), when the FTR web service tries to evaluate the vault host as the fully qualified name, the SPFServer host will be evaluated and this results in the FTR webservice trying to make a call on a remote host and it fails.
Solution
You must use the same host name, which was mapped with the IP address in the hosts file on the Vault.