Hi,
I have a mod I'm developing and change the base rails recipe to have wood as an ingredient. This causes an issue with this mod when it goes to duplicate and then alter the recipes for its own railways:
Error while running setup for recipe prototype "bbr-rail-wood" (recipe): Duplicate item ingredients are not allowed (wood exists 2 or more times).
.
Edit: Actually, don't do anything about this, yet. I'm going to see if I can solve it from my side. This mod makes its bridges only from the base rails. As I've made these rails now inferior to a couple others I've added, I should see about adding upgraded variants of the BBRs, in which case I can (hopefully) also fix the recipe at the same time.
Edit2: Yup, I managed to take care of it. You can ignore this. :) :P