I was using the fill in command and minecraft crashed and I got the error code ce-38700-8 blue screen of death, I check my save data in the settings and I saw corrupted data with minecraft. Thankfully it was save cache and not the world itself. I spent 4 hard years on my world. Also please patch this fill in command bug not filling in completely, the game will freeze up and not fill in entirely. 

How to produce: 

When you go to the fill command type in the coordinates you want and if it says 32,000 blocks filled sometimes the game will freeze and crash.