I was working on a game of mine, when all of the sudden the world was hit with extreme amounts of lag. My camera was jittery, mobs were slowed and buggy, and was overall very laggy. I started a new world think it would fix the issue, and was wrong. On a brand new flat world with no experimental features, addons, or texture packs, I still got the extreme lag. When I exit the world, the lag is so bad it causes the world size to go from around 15 megabytes to around 250-300! Keep in mind that the worlds I am referring to are brand new flat worlds, with NO experimental features OR addons/textures of any kind. This bug is catastrophic, and must be fixed!