what's wrong with this Volume component

 I got some ramdom points in rhino. and i apply this points into the voronoi system. and i want to get the 3D  voronoi Skeleton.But i got a problem that the the surface of the 3D voronoi Skeleton on the boundary is not closed.

In the gh, the component VOLUME is orange, it says "Brep is not closed, volume results are not to be trusted. "

I don't know what wrong with it.