Object reference not set to object

Pretty confused, been attempting to follow the youtube videos of how to use the nesting pluggin. I did the manual work to get everything to 2D geo. but consistently get an error around it “not being an object”, from what I’ve read in other forum posts the shape isn’t closed, but as far as I can tell it is. So to make it short, I have no idea how to nest this properly, help would be greatly appreciated

Initial Shell Study 2.0_re.gh (20.8 KB)