Factorio Forums

I ran into a bug with stone furnaces. When I open the UI for it and click z to place a single coal in the fuel spot the coal disappears from my inventory but does not appear in the furnace, it seems to just be gone. I am running the game on Mac OS, Apple Silicon M2 Pro. Game Version 2.0.10 build 79578 mac-arm64 with space age.

Z usually drops an item on the ground (at the position of the mouse cursor). If you want to place a single item (coal in this case) into a specific slot (furnace's fuel slot), you can use RightClick - in the Controls settings it's called Cursor split.
However, it's still possible to use Z to fuel the furnace. Just hold the stack of coal, hover the mouse over the furnace (without opening its UI) and press Z.

Yes you are so right, guess it's been too long since I played! Thanks!