Fix a bug on my site which uses the 9gag script

My site is [login to view URL] and it uses the same script as [login to view URL] Now here is the problem, when you try to sign up with facebook by clicking on the green button it goes ahead and works but it doesnt connect through facebook it just asks you to accept the application permission which i already created and connected Instead it just asks you to make a regular user account, then if you sign out and try to log back in you get a fatal error or get sent to a 404 page :/ I need someone to fix this as soon as possible please Thanks!