UUNP neck has a weird "lump"

[Pacal_II]

I have a mesh problem. Even when I don't use any textures at all, when I do a preset in bodyslide the neck has a weird blocky shape, as you see on the right image at "weight = 100".

The odd thing is that this doesn't appear when I use the default bodyslide body without making my own based on a preset. It also appears no matter what preset I use.

I can just cheat and transfer the setting from weight 100 to weight 0. Or even switch them if I still want the variety in bodies. But that will still make half the women in Skyrim half that problem.

 

[Unmotivatedpride]

What it looks like is as if the head scales for weight but the body does not. 
I've tested some armor before and temporarily had _0 and _1 as the same file and at 100 weight that's how the neck looks.

However if you're using bodyslide it really should be making the neck widen for _1 automatically. So I can't really guess how that's how it ends up.