When clicking on the double furnance, it shows "Unknown key: "recipe-name.double-iron" (Recipe)".
Seems to be cosmetic only. Is this a localisation bug? I play with the standard english factorio
Where do you see this? Can you provide a screenshot? I wasn't able to find the place your referring to, when I click on the double furnace it shows the correct strings for me in all UIs, so I'm not sure what I'm missing here 🤔