What I expected to happen was...:
To load up a MC 1.9 superflat world(not customised) and play with new blocks.

What actually happened was...:
Once clicking "Create new world" I crashed. No crash report but its a java runtime enviroment fatal error.(report below)

Steps to Reproduce:
1. Load up MC 1.9.0
2. single player
3. Create new world
4. set super flat (do not customize)
5. Creative
6.Create world.
8.Game crashes

http://pastebin.com/4NDx43dz for launcher report.
for error file(notepad):http://pastebin.com/PwmfAMHN