Error when logging by Facebook - Given URL is not allowed by the

I'm getting the following message when trying to connect by using Facebook

Given URL is not allowed by the Application configuration.: One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains.

How can I fix this ?

Probably the domain names don't match that you set up on Facebook and in JFBconnect settings. Haven't you recently moved to a different domain name or use WAMP, XAMP?
Try to also run "Auto-Tune" in JFBconnect config.