Hi Alex,
my site sometimes got the following 2 errors these days:
This one appears after user click "agree" button when register and no new user can be created in Joomla(but the facebook account has added the permission setting). If I enable Require Email Permission option, the problem gone. But I don't want to enable it now.
The email address is not valid (not exact words)
This one appears when some users login. Users can login but give following message. Maybe these users have many facebook account.
Facebook API Error: Invalid OAuth 2.0 Access Token
Please help explain why these message appears=] Thx