Put the summary of the bug you're having here

*What I expected to happen was loading a huge custom map and load it into 1.9. But probably the world was made in 1.8? anyway the world did not load and MC crashed now it will not load MC at all anymore. Any version !!!
Just crash and start all over. Not make MC useless

*What actually happened was It made my MC installation corrupted and useless
Describe what happened here

Steps to Reproduce:
1. Download this world http://download702.mediafire.com/a1q90k8bb9yg/swk33nreumeq6sm/Custom+4K+Map.rar
2. unrar it.
2. Place it in the saves directory
3. Startup minecraft 1.9
4. load the world
5. world doesn´t load correctly instead it crashes Minecraft
6. Minecraft will not start, at all, again in any version.