Have you set your output stream to Facebook's recommended settings? same for audio?
Then there is the stream key. I started with Persistent key, but then moved to non-persistent key for better security.
One foolish newbie error I made was initially logging into facebook.com/live/producer [you do know about this page, right?] and not switching the page to the account to stream from but instead the default (and wrong in this case) personal account... depends on what you are doing whether this applies
then are you scheduling a live event? if yes, are you following Facebook's rules, especially being connected in advance
