Modular character weird deformation

So I have been working with the Paragon assets, trying to break some of the characters down into modular pieces to use as armour. I have both meshes using the same base UE4 skeleton and when you view them separately everything looks fine, but when I overlay the base character with the armour component I am getting deformation around the neck. Anyone have any idea how I can fix?

Thanks

I have also seen errors with many programs that use modular characters I think it is a skeleton mesh merge error but I am not sure all I know is it makes almost all unreal engine games unplayable and puts strain on my system due to extra rendering.
Here are a couple different examples from different unreal programs
I have looked in dxdiag made sure nothing was corrupt, changed settings, updated drivers, etc…
Three different developers don’t all have the same fault in their code I have more examples from other projects but I don’t want to just bombard the website with them