https://prnt.sc/1175h0n

I can't reproduce this on my end. It might be a compatibility issue with some other mod. Could you maybe try to figure out which one, so I can look into it?

Most likely this is a load order issue.

you make it very easy for yourself! first lock at YOUR code and you will see where the problem is.
https://prnt.sc/11af1qg
don't assume the item.icons is always a table. it can be nil.

From the wiki: "Either icons and optionally icon_size, or both icon and icon_size have to be specified".
So there are several options:
- some other mod isn't following this standard and leaves both icon and icons as nil
- some other mod only sets the icon in the final-fixes stage and loads after this mod (most likely option)
- in some case that I don't know about, IconSpecification isn't a mandatory property

Unless I know which mod/combination of mods is causing this, I can't figure out how to fix this properly. I don't want to blindly throw in safeguards without being able to test if they actually fix the problem.

It was just a polite request since I don't have much time on my hands right now - you seem to know how to code and this is a pretty small mod, so I thought that you might be able to help figure this out (narrowing down which item is causing this for example)
You could also give me a savegame so I can do this myself.

I honestly need more info than just a screenshot of the error message. Otherwise I'll have to treat this as not reproducible.

I use over 160 mods, but what good does it do you to know which mod doesn't set its icons correctly? it doesn't change anything about the crash in your mod. you should fix this generic (and skip this signal without icons).
But its you decision. I don't like such time-consuming discussions, in the meantime I might as well fix it myself.

I use over 160 mods, but what good does it do you to know which mod doesn't set its icons correctly? it doesn't change anything about the crash in your mod. you should fix this generic (and skip this signal without icons).

That's why I said that you could give me a savegame - that way I can easily download all 160 of your mods and check it myself.
I added an error message for this case - please tell me what it says.

https://prnt.sc/11c4ept