I was testing something with hoppers and I thought that an active redstone signal would stop hoppers from moving blocks/items (I'm a redstone newb).
So I put down a track of redstone and connected it to two hoppers, standing next to each other. I flicked the lever and everything was fine. Then I entered the hopper menu and before it could open the game crashed.

Steps to reproduce:
1. Go to a Superflat creative world.
2. Put 2 chest in the ground, and 2 hoppers above them.
3. Make a redstone signal for both hoppers that only takes 1 lever.
4. Flick the lever and open the LEFT hopper.

Beware to put everything the same as in the screenshot, the right hopper works as it should, the left doesnt. ( THe orange things under the hoppers are chests )