Crashing

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
I thought when i clicked demo version it would come up as minecraft like the person i am following on youtube.

What actually happened was...:
Describe what happened here
I clicked it and it constantly kept on crashing.

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. I loaded up the minecraft Mojang gave to me
3. I logged in and clicked demo version
4. It crashed, so i clicked report bug.