The developer has stopped supporting this app unless you send him a contribution. That goes contrary to everything related to open source ethics. Therefore, despite a good ap, it gets 1 star from me. I refuse to donate to a project that I can't get working in the first place.
There appears to be a conflict between the ap and WordPress now, which interferes with authorization on facebook.
The error is as follows:
[sensitive data redacted] — Mod edit
It may be down for maintenance or configured incorrectly.
Now using the plugin on another WP website and it is functioning well. Raised my rating to three stars. Still miffed that the developer won't provide support until after one donates. Still thinking about whether I'll donate or not.