Closed Surface Inside Closed Surface

Hi,

The basic problem here is that we have a solid that contains a closed hole inside it. We have all the surface meshed in 2d mesh. When we are trying to create the 3D mesh. Hypermesh does not recognize the outside volume. It only recognizes the inside hole and meshes it as a solid.

I have two basic ways to bypass that problem. 1) Use the volume meshing instead of '2d meshing and then 3d meshing'. 2) Add a tiny little hole in the original volume to make the inside hole not closed anymore. 

I am wondering what are the reasons that causing that problem? How does hypermesh define the geometry? (I am always wondering why we can release the points in hypermesh) And are there any other more solutions to the problem?