Crash loading/creating world

Put the summary of the bug you're having here

What I expected to happen was...:
I expected the game to load.

What actually happened was...:
I started a world of survival and Minecraft crashed.

Steps to Reproduce:
1. Start up Minecraft with JVM Arguments -Xmx100M
2. Create a new world with the world name "Man Vs Minecraft
3. Game begins to load.
4. The game should crash.