clothing mesh showing skin texture

I'm trying to shorten a base game skirt and I made the texture and mesh shorter, but when I put the new texture and mesh in s4s a section from the original mesh that I deleted is there but with skin texture?

I had to put in new legs when I was making the mesh shorter in blender and there wasn't any problems but when I put it in s4s the section from the original mesh makes the new legs dissappear.

if anyone can help I'd really appreciate it