furnace wont work

Put the summary of the bug you're having here
furnance wont place coal or take out items
What I expected to happen was...:
Describe what you thought should happen here
allow to place coal and take ou items
What actually happened was...:
Describe what happened here
i couldnt take out the stone or sand and i couldnt place coal
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...put stone in
3. ...click the bottom slot in funace