Facebook App: «Can't Load URL: The domain of this URL isn't included in the app's domains»

I followed these directions however there seems to be some updates made to the facebook app developer page and they don’t align with the above instructions. I keep getting this message when I try to log in to my forum using facebook:
Can’t Load URL: The domain of this URL isn’t included in the app’s domains. To be able to load this URL, add all domains and subdomains of your app to the App Domains field in your app settings.

Does anyone have an updated instructions on how to get this done?


Still getting the same message.

From now on, I provide my external authentication configuration service.