World turns black enabling you to only see certain blocks e.g lava and water. Only certain items in inventory show up, some apear to have broken textures and some have none at all e.g Red sand

What I expected to happen was...:
I didn't expect it

What actually happened was.
Just found a new Mesa Biome was really super happy decided to mine out some Red sand and then suddenly the darkness happened :'(

Steps to Reproduce:
1. I have no idea, On YouTube Etho experienced a similar fault but fixed it and I don't know how! :'(