The version checks are done primarily against the domain dbFront.com. The domain vc.dbfront.com is a fallback domain coded into dbFront in the event that dbFront.com is not reachable or if I decide to move some services to another server or host.
I will look at improving the error details and message.
If the error is ongoing then the most likely source of the error is that access to dbFront.com is blocked from the webserver.