What I expected to happen was...:
To put my armor into a blast furnace and receive an iron ingot.

What actually happened was...:
I put my armor into a blast furnace and the game crashed. When I logged back in I was able to receive an iron ingot, but taking it also crashed my game.

Steps to Reproduce:
1. Make a wall of blast furnaces
2. Put armor into one of the blast furnaces
3. Fuel the furnace

If this is a bug and not just a problem specific to my computer, the game should crash with the error message of "The game crashed whilst ticking block entity"