World not loading

Yesterday, after having downloaded the 1.9 update, I have opened a map I have been working on for 3 years (more than 200mb), and the world appeared totally white without generating blocks. I could move around and interact with the blocks but I could only see the torch particles. I then decided to open the inventory and it froze, the game showed a loading bar. I refreshed the app and tried to access my world again, but it doesn't load. The green loading bar just stops, even though the app is still working, and I cannot access my map. 

I have removed all texture and resource packs (I was only using one texture pack). But it still doesn't work...

(All my other maps work perfectly...)

Please help !!