Hi Chris,
I am really sorry for the delay of this reply.
I believe the issue is occurring because you are using quite older version of easyblog 3.9 (not the latest 3.9) where the facebook API does not get updated in that version. If you are using easyblog 3.9 on the site, you can try download my attachment below and place it inside your /components/com_easyblog/classes/facebook/ folder and then try to re-authenticate again.