Yes, it is. And I found it out the hard way. You can find my progress here:
https://mods.factorio.com/mod/upgradable-lightning-rod

I have marked it deprecated so people cannot download it the normal way. I have already added the missing next_upgrade key but then the game required me to add fast ...

So how about adding upgrading lightning rods -> collector as a mod? I think all what needs to be changed is to add to the rod item entity and then an upgrade planer can find it?

So okay, this issue has already been addressed. Let's then close this as [invalid].

Meh, for 2.0.35 i added one check for malformed ingredients (in quality/prototypes/recycling.lua) and one check for malformed products (in core/lualib/util.lua)


Ah, thank you. Yes, sure disabling quality mod should lead you do the faulty mod data. I can go with that, too. It just didn't came to ...

The mod quality wasn't the culprit and it was shown with the other mod were the error was but it wasn't mentioned here.Adding some more log() calls isn't a hard task to do. But still it took me hours to find this out, that results can hold a list tables (not must?). So you cannot see the mod (FE+) I ...

It took me hours to find this bad mod data so I ask you if you can add some validation in function core/lualib/util.lua, normalize_recipe_product() .

So let me give you a simple example to how to reproduce it:

Write a recipe with results = {type="item", name="foo", amount=1} (yes, the list around ...