<BETA for Factorio 2.0> Choose what you want to produce and this will tell you the main cause why you are not making more of it.
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.
Furnaces, assembling machines, production chains.
Unable to save map: Mod What is really missing? (3.0.1) caused an unrecoverable error.
Please report this error to the mod author.
Error while running event Kux-WhatIsMissing::on_save()
Cannot serialize lua functions
-2 hours of play
Yup, this is the main reason why I haven't updated my mod yet (which this mod is a fork of).
I know. simply wait until the async operation is fisnished. and than save again. currently a safe save rework is in progresss.
BTW should be fixed