I can log in to Minecraft fine, but when I click on my world the screen flashes for a second and then the game closes itself down. I am only having this problem with the new launcher, with the old one it was fine.

Put the summary of the bug you're having here

What I expected to happen was...:
The world opening normally

What actually happened was...:
The screen flashed for a second and then the game closed itself down.

Steps to Reproduce:
1. Download the new launcher
2. Try and click on a world