Unfortunately, at this time, you won't be able to login with Facebook. This isn't a vbullein issue. It seems that Facebook is discontinuing v1.0 API and forcing everyone to move to v2.0 API or greater. As soon as the latest update of vbulletin is available, I will update it and try to get the facebook login working again. We apologize for the inconvenience.

To read more about the Facebook discontinuation of v1.0 API you can read more about it here: https://developers.facebook.com/docs/apps/faq#migration.