How do I change type and graphics for the raw-fish?

Factorio uses Lua to mod, and I had a question about it.

I'm trying to override raw-fish so it changes the type and graphics, but I can't find anything online on how to do it. When I try loading the game with the mod installed, it shows the error:

"Error while loading item prototype "raw-fish" (capsule: Prototype "raw-fish" registered twice"

Any help will be appreciated, as I'm fairly new to modding in general.

Solution 1:

I think the error is from the name you're giving to your item which is exactly the same as the original. You should try to give an other name instead to override it, or to modify the original Raw-Fish ?

This topic on the official game's website is about a similar problem you have. You can test some solutions and apply the one that fits the most in your case.