The game do strange thing/flash

I was in 1.9, I loaded a world that was in 1.8 and when I go in the world, some biome flashes and place random block every second.

What I expected to happen was...:
Normal biomes

What actually happened was...:
Strange biomes that show random block that change every second

Steps to Reproduce:
1. Take a world generated in 1.8
2. Go in 1.9
3. Go in this world
4. Check around you, it will have some glitched biome somewhere.