Furnance crash

Put the summary of the bug you're having here
Crash by using my furnance
What I expected to happen was...:
Describe what you thought should happen here
to be abble to put my coal ore in the specific slot
What actually happened was...:
Describe what happened here
instat closed the game
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...right click the furnance
3. ...put coal ore in the specific slot (in any way)