If you are having issues using Facbook authentication on a Mac app you may not have updated your configuration within the Facebook developer console.
You are most likely getting an error similar to the following:
Under this guide Facebook state:
redirect_uri. The URL that you want to redirect the person logging in back to. This URL will capture the response from the Login Dialog. If you are using this in a webview within a desktop app, this must be set to https://www.facebook.com/connect/login_success.html
If you’ve been using PhFacebook there wasn’t anything you had to do until now.
However if you have been trying with a different redirect_uri, fix this up now and keep reading.
The change (it seems) is that you are now required to explicitly set the redirect uri.
Go to apps and select your project > Settings > Advanced > Security > Valid OAuth redirect URIs.
Enter the following url and wait a minute or so:
That’s it, test it out and hopefully it’s working for you now.