Game can not tell you if a fluid with the same name as an item is missing.

[CPU_BlackHeart]

Pretty much what it says on the title. If you're modding and you create a fluid and an item with the same name, if you have a type=item of myNewItem, but forget to make the type=fluid which shares the same name as myNewItem, Factorio can not tell what exactly the issue is and will instead output an error with the "Quality" mod. This can make it difficult to determine what the issue is when you're making a lot of items/fluids and don't test every 2-5 minutes.

[Rseding91]

What? There are tons of items that don't have a matching fluid of the same name. It's not a requirement of anything.

[robot256]

The title is incomprehensible. The only way to explain what you mean is break down what you did step by step and where your expectations did not match what you observed. Are you talking about item/fluid prototype definitions, or item/fluid ingredients listed in a recipe prototype? Do you mean the fluid definition is missing, or is it there but with incorrectly-set type="item"?

[Thremtopod]

This sounds to me like: if a mod references a fluid that doesn't exist, but an item of the same name does exist, the error message doesn't explain it. So for example, if you add a recipe ingredient with type = "fluid", name = " iron-plate" you'll get a confusing error message.

[Rseding91]

This sounds to me like: if a mod references a fluid that doesn't exist, but an item of the same name does exist, the error message doesn't explain it. So for example, if you add a recipe ingredient with type = "fluid", name = " iron-plate" you'll get a confusing error message.

You get an error stating: "Error in assignID: fluid with name 'iron-plate' does not exist."