Problem Using ExoW

Hey Guys,

I am having a problem when joining two wireframes into one Exoskeleton Mesh. As you can see in the Pic#1 I was able to thicken the wireframe while having a problem after mirroring the wireframe along XY plane.

The ExoW component keeps saying : "Solution exception:Object reference not set to an instance of an object."

I exploded the geometry to see which part causes the problem end up finding problems at points 0,1,6,7, basically all the boundary points. It seems to be an easy geometry and I would really appreciate if someone can shed some light on my case. Thanks.