I have logged logged in to my original account in facebook and it just doesn't let you play, it does load however, but after showing you that it does load, and after the "Loading Your Survivors" phase, it just gives you a black screen.
However, I logged in to my other account and played the game and it worked! So I think the problem is now with your servers and not on my part.
Hope that you can get this fixed ASAP :) I've been reading the forums with similar problems as mine and you replied to them, hope that I get the same response as they did.
Regards to the Team :)