Zombie Villager cannot be cured if you play beta and you have ticked Cave and Clifs update in menu.... you cannot cure Zombie villager and baby zombie villager even if you first turn them zombie by killin with zombies you just cannot cure them, it doesnt work with bow and arrow of weaknes neither with potion. If I make new world and do not tick Cave and Clifs option it works but if I do it doesnt. The problem is Golden Apple... you hit them with arrow then give them apple and game just crash..... it shut off minecraft in second. if you try again it happens again and so on.