So I was trying to find iron for a while and I realized I had already found iron to pick at the gold with. Anyway, I went to take my iron ores to the furnace and placed them in the correct spot. That worked but then I needed to select the fuel I wanted and found that I could not select anything nor could I place them in the correct spot. And one more thing that is wrong with the furnace is that the product that comes after the combustion process is also unattainable. Which is bs.