URL is not allowed by the Application configuration.

I have a website with facebook login. It has been stable and working for months. No code change has happened for weeks. Then, suddenly, the facebook login gives an error message:

Error 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.

Same problem with me then i do this... After debugging "for awhile", I reset my facebook app secret and it started to work again!