Annoyance with "Paths must have at least one element"

Hi,

I have certain "Branch" components that don't necessarily receive a path input, and I dont mind them being red.

The problem is that it gives me an error message each time I open my definition : "Paths must have at least one element", and I need to check the "Do not show this message again" option, or else it goes on forever.

I noticed that the items in the paths were "<empty>" (not sure how this is different from "Null" though), so I thought I'd remove the branches with a "Clean" component using the "Empty" option, but that does absolutely nothing.

What should I do to get rid of the nagging ?

Cheers,