Minecraft Launcher 1.3.7 crashes after attempting to play and sends a crash report.

Put the summary of the bug you're having here

What I expected to happen was...:
That the game would start after I clicked play on the 1.3.7 launcher.

What actually happened was...:
The launcher crashed during the process and showed me a detailed report.

Steps to Reproduce:
1. Start 1.3.7 Launcher
2. Click play
3. Minecraft Crash Report