Game crashed! Also <World> bug when loaded back up!

Superflat (Snowy Kingdom) with only Snow (Decoration) as a layer

What I expected to happen was...:
It will run normal like always

What actually happened was...:
The game crashed. When I went back on the map, there was a massive line without any Snow on the floor.

Steps to Reproduce:
1. Create a Superflat world, choose Snowy Kingdom as the preset.
2. Delete all layers except from Snow (Top)
Any other option (Eg: Bonus Chest) you can turn on, if you want
3. When map loads, destroy a Snow & it will happen.
4. When loaded up again, there will be a massive line. If a Snow is destroyed again, you will end up at Step 3 again.
(Where it starts at the bottom, this is my spawn point. I tried it twice, that's why there's 2 blocks of lines missing)