The error indicates that the application in Facebook is not set up correctly. Please set up an App Domain in your Facebook application in the Settings > Basic area. Likewise, you can use the Autotune Configuration Tool in JFBConnect to correctly set this value (assuming you've turned on the "Allow API Access to App Settings" option in your application.
I would suggest reviewing our
application setup guide
to make sure you have followed our guidelines to get started.
-Melissa
Error re Facebook
