Put the summary of the bug you're having here

*What I expected to happen was when I exit a wrold and enter another all the chunks and mobs should load.

*What actually happened was when I exit a wrold and enter another all the
Mob and chunks went haywire one of the chunks duplicated and that was every single jump in some of the mobs bodies were only half there and Sons had were on the ground legs in the air
Steps to Reproduce:
1. Join a world single player or multiplayer
2. Exit that wrold
3. Join that world or another