Factorio Forums

I'm trying to add additional tiers of modules.
When I load the game I get "Error in assignID, item with name 'itemName' does not exist.
I've checked, double triple and quadruple over the files for any discrepancies between each module but I haven't found any.
I only made a item/recipe/technology module.lua, but no entity one because the base game did not have one.

I'm just really stuck and tired at the moment, and my search efforts have been fruitless so far.
Any help would be greatly appreciated.

Can you upload the mod as you have it now? Without the code is difficult to say what's missing.