Entity Crash

I opened my minecraft 1.8.3, then gone in to the world in creative, spawning entity and then it crashes for some reason! Can any1 help me!!!! Bug Report: https://docs.google.com/document/d/1ZkG_bGThu6XyuXn19PnRwQKDOjD9wnFVRs8357XWOjc/edit