Some more information from the WC logs: each failed authentication attempt logs this message:
09-18-2017 @ 23:11:48 – HybridAuth Error: Endpoint: Error while trying to init Hybrid_Auth: You cannot access this page directly.
Help! I need this to be resolved as well. I have a live e-commerce site that can no longer use Facebook login. I get the error “Provider authentication error”.
I can confirm that my Facebook app is public, the app ID and secret are correct in the WC control panel, and that the site domain is listed in App Domains and my email address is the Contact Email in Facebook.
