Okay, neither the Facebook nor Twitter login will behave, and I cannot find documentation to tell me what to do. Yesterday the FB sent back an error saying that I didn't have the domains in. The only place I could find to put in a domain was in the app settings, but it was not clear what domain they wanted when they said "app domain". So I put in the website domain. Same error.
After trying everything I could to find an answer, I deleted the app and created a new one, figuring that i had missed something in setup somewhere and would catch it this time. Now I don't get that error, but the FB button doesn't respond at all.
Then with the Twitter login, it said that the token was expired. So I regenerated that (how often does that have to happen??) and now a small login window pops up, but it takes me back to my site with nowhere to click or finish the registration.