Put the summary of the bug you're having here
What I expected to happen was...:
I expected to play the world regularly
What actually happened was...:
The world had succsesfully loaded for 10-20 seconds and it suddenly crashes
Steps to Reproduce:
1. Click "Play" on minecraft launcher
2. Click Play World on that particular world.
3. After 10 secondsof fully loading the world, It crashes !!
It happens to me too. Crash report says: "n" must be positive. What the hell is "n" variable and why it makes the game crash after some seconds, but not instantly? Nobody knows...