As soon as it downloaded, it crashes~

Once it was downloaded we thought we would be able to play game. It crashed as soon as it downloaded. We do not know the problem!!!
/What I expected to happen was..we would be able to play game
Describe what you thought should happen here should be able to play minecraft.

*What actually happened was...:*it crashed.
to Reproduce:*
1. Put a step by step guide on how to trigger the bug here
2. ..?
3. ...? you tell me--its your game that I'm paying for.