Factorio Forums

I'm making a mod that (among other things) adds fluid input/output to steel and electric furnaces. They seem to work if placed separately, but in testing on a real game, the game crashes when placed on top of existing stone furnaces to upgrade them. This crash is probably because I misconfigured something in my mod, but I'm reporting it on the off chance it's not.

What did you do?
Placed a modded steel furnace on top of an existing stone furnace.

What happened?
Game froze for a second or two and then crashed to desktop.

What did you expect to happen instead?
Steel furnace to upgrade the stone furnace in the same way as base game.

Does it happen always, once, or sometimes?
Always, placing a steel furnace on any of the stone furnaces in the autosave crashes the game.

Luckily I had an autosave right before this happened. It can be reproduced by placing a steel furnace on any of the stone furnaces right above the player when loading the save. From what I can tell from the log file, the game crashed when transferring over the in-progress smelting recipe. This is probably because I messed something up in the mod, but again, reporting just in case it isn't or this isn't the intended behavior.

Thanks for the report. I found what the issue is. It was introduced in 2.0.50 - when you are fast replacing the furnace, empty item stack for the products are attempted to be inserted into the new furnace, however since the item stack is empty it does not match any product item stacks of the new furnace. It does however match the fluid stack due to empty ItemID and this causes the crash.

Issue is now fixed for 2.0.56.