Minecraft 1.7.10 World not loading

I was trying to open a world in 1.7.10 then a crash report came up. I tried everything! I tried recreating a world, making a new fresh world, and I tried opening a world that already existed but it still crashed please help! (I had to lie about the version this bug was on to get it to work sorry!)

What I expected to happen was...:
to be put in my world

What actually happened was...:
I got a crash report

Steps to Reproduce:
1. Open Minecraft 1.7.10
2. Open a world
3. See a crash report