Hull shell model- error: branched edges when using loft function

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Hi, I'm trying to modell the hull of a ship. I have 3 of the decks, but when trying to use the loft function I get an error saying that the area I'm choosing has branched edges.
Does anyone have ny tips with this?

I do not fully understand why I get this error. The area can not be a loop, therefore I feel the area must have branches.
Is this as simple as that the loft function does not like the form of the edges I choose? Too complex shape...

Any comment is appreciated.

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