I got this not-helpful error message when posting new content:

Failed posting to your Facebook Timeline. Error: {“message”:”(#100) You haven’t enabled Explicitly Shared for this action type (331247406956072) yet. Please update your Open Graph settings in the App Dashboard”,”type”:”OAuthException”}

I found the solution here:

http://stackoverflow.com/questions/18532418/facebook-social-publisher-stopped-publishing-to-timeline-with-message-about-enab