Placing a furnace in the world and attempting to load coal or other fuel sources into the lower slot cause the game client to crash.
Placing a furnace and a hopper on the side allows you to load fuel into furnace for smelting/cooking.
Issues present in End, Overworld, and Nether Dimensions.
Known tested items for crash - Sticks, Logs (any type), Coal, Charcoal, Wooden-Tools.
Crash is instant and very repeatable.
Environment
macOS Sierra 10.12, java version "1.8.0_91" Java(TM) SE Runtime Environment (build 1.8.0_91-b14) Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode). Verified in Windows 10, Java 1.80_101 on seperate machine.
I have successfully loaded all types of logs into the furnace. Coal, and Charcoal do not work when placed manually.