Starting up a 1.4.2 world, and the game randomly crashed

What I expected to happen was...:
that the old world save would still work

What actually happened was...:
5 seconds after loading the world crashed, with just the dirt screen up.

Steps to Reproduce:
1. Click on old 1.4.2 world
2. load up 1.4.2 world
3. Wait 5 seconds or more
4. Game Crashes