after i select a world to play it loads 100% and then crashes without entering the world

Put the summary of the bug you're having here

What I expected to happen was...:
the selected world to open

What actually happened was...:
after opening the selected world it should load but it crashes after giving the message "saving world"

Steps to Reproduce:
1. click play and open minecraft
2. click play game 
3. select world- "Rishabh"                                                                                                              

4.game will load to 100% and then crash