It Shuts down during the demo

Put the summary of the bug you're having here

*What I expected to happen was...
Describe what you thought should happen here
:The game would start and it would go on rain a little sunshine would come I would mine some iron all that stuff
*What actually happened was...:*Describe what happened here :I hit the play demo world button it loaded the world and the game stopped working

Steps to Reproduce:
1. log in
2. ...play the demo
3. ...hit the play demo world button
4. ...when the world loads it freezes and ends the game