Put the summary of the bug you're having here
What I expected to happen was...:
The world would open normally.
What actually happened was...:
The world opened for a second, then the game crashed.
Steps to Reproduce:
1. Download Death Sentence Arena Map- I downloaded it a couple of updates ago and played it a few times, but with the snapshot it does not work.
2. Try opening it- It works up to 13w19a, but crashes in 13w21a and 13w21b