Background is not toned when opening a furnace

Put the summary of the bug you're having here

What I expected to happen was...:
The screen behind the furnace is supposed to be darkened during interaction.

What actually happened was...:
The screen was not darkened but the interaction menu still opened.

Steps to Reproduce:
1. Interact with a furnace
(A screenshot of what happened: https://puu.sh/vg36n/8b42af4459.png)