Can't seem to get this to work at all.
I have followed the insturction in the setup here: documentation.jomsocial.com/wiki/Setting_up_Facebook_Connect
Everything went fine. They have changed a touch on Facebook, but this is always being done. :)

My website is: www.redtalkers.org/
With the JS Hello me

The Community is: www.redtalkers.org/community

Template is JA Social II
Jomsocial 4.5.1

Hi
As I can see the configuration you applied on Facebook is not correct.
Have you added your domain after adding facebook login on facebook app here > prntscr.com/i48coj
Here: prntscr.com/i48doh
On your site I am getting the error : URL Blocked: This redirect failed because the redirect URI is not whitelisted in the app’s Client OAuth Settings. Make sure Client and Web OAuth Login are on and add all your app domains as Valid OAuth Redirect URIs

Let me know if it helps.
Otherwise, i will create a test key and will try it on your site.

Regards

Hmmm ok here is a pic for you prntscr.com/i497d7

Hi
The login is working on your site prntscr.com/i49kqx
I tried to my login and its working normal: prntscr.com/i49l1f

PS: i deleted my account after testing.

Regards

Well in this case I will delete it on facebook and redo it. Not sure what I have done wrong at this point.

Just redid everything and you got me. I am stumped at this point.
here: prntscr.com/i4gnjr
here: prntscr.com/i497d7

Hi
You facebook does not allow me to log in on your account due to security issues.
You facebook login was working fine, seems you deleted the app.
Kindly re-create it as i suggested and add the new key in Jomscial.
Error: App Not Setup: This app is still in development mode, and you don't have access to it. Switch to a registered test user or ask an app admin for permissions.

It seems either the app is deleted or you are using incorrect keys in Jomsocial.

Regards