You cant get items out of furnaces.
Put the summary of the bug you're having here: you cannot move the highlight in a furnace to the fuel area. You cannot take items out.
What I expected to happen was...:
The items would come out. The highlight would move
What actually happened was...:
The items stayed. The highlight didn't move.
Steps to Reproduce:
1. Open furnace GUI.
2. Place item(s) into furnace.
3. Try to remove items
4. Try to move highlight to the fuel