I have built a mob grinder, but nothing is dropping down, and when I go to the top of it, there is no mobs. I know EMC made some edits to vanilla, the 64 block's spawning. I am in the 64 block radius and the grinder is less than 35 blocks tall. Still nothing is spawning. I have tried this design in creative mode and it worked, why won't this one work? I have rebuilt a different design and both still aren't working. I don't want to remove the grinder, because I just spent 3 hours making it/getting materials. If a staff is available, I could show you where it is.