When I was playing still on 1.7.5 all was working well. When I updated minecraft to the newest snapshot 14w10c, mobs in XP farms are not spawning. For example in my endermen farm endermen are just not spawning. Previous they were spawning like crazy ! In the nether Zombie pigmen are not spawning as well . Specificly in my Gold farm ! If this is not a bug with the newest snapshot than I don't know what it is And of course my difficulty in my world is set to Hard in survival mode. Anything in the options has not been changed since i updated to 14w10c snaphsot . Waiting for the BUG fix Thank you very much !