I got a new error today, possibly after a bunch of angel updates:

data-final-fixes.lua:268: attempt to index field 'expensive' (a nil value)

Any ideas ?

Hm, that's weird. I have a modpack made just two days ago that includes not only all bobs+angels, but also some omni mods, and it loads up just fine. Angel hasn't made any updates since then, so it's definitely not them. I even have Yuoki on top of all that.

Must be some lesser used mod? I would need a list of any mod you're using that might add recipes

As possible additional information, I just received this error after updating to 15.27. Before, it was working fine...

I've updated Factorio to the latest (currently 15.28) with the same modpack referred to above. Whatever the problem is, it's not part of vanilla or the list of mods I'm currently using. I would need a modlist to check personally what the problem is, or use the tried and true "remove a mod, check if it loads" to tell me which mod is the problem

It seems that the other offending mod has been updated, and everything is working fine. Thanks for checking into that.

So I've been getting this error as well. I've narrowed it down to being caused by the Natural Expansion Buildings mod and your mod enabled at the same time.

The particular error I get is __reverse-factory__/data-final-fixes.lua:261: attempt to index field 'expensive' (a nil value).

I am also running factorio at version 0.15.28

THANK YOU. Although for once, I think the error is on the other end, not on mine. The problem seems to be that the author has defined a bunch of "normal" level recipes with no "expensive" level counterpart. This doesn't happen in vanilla, so I didn't plan any catches for that. I still don't think I should, since there's no point in defining a "normal" level recipe without an "expensive" level counterpart.

It seems to be a typo, from what I can tell, as there are defined sections for what should be expensive recipes, they just don't have the "expensive = " part before it, though he does have it on others. I assume it's a failed copy-paste on their end.

I updated to make it more visible that there is another problem mod in this situation (and to make it easier to identify which recipe is the problem). The conflict will have to be resolved from their end though

EDIT: The error has been fixed from their end.