Board Thread:Help!/@comment-25357311-20140828025257

i just started playing NTerraria yesterday and so far its been amazing but i just got to hell today to get to hard mode. i've killed the wall of flesh probably 4 times now and it said that the ancient spirits of light and darkness denied the sacrifice rather than the being released. i just wanted to know if this isn't in the game yet or if its just my game. and any advice on how to fix it would be great thanks! 