Creating solids from Rhinoresurf plugin

Hi All,
I didnt know this forum exists. I am relatively new to Rhino but learning fast.
The challenge I am facing at the moment relates to the RhinoResurf plug in for NURBS surfaces. I Basically have a point cloud data I am trying to convert to a solid CAD model for further analysis in Abaqus. I have a point cloud data of a surface from a laser scanner. Because its a surface data, I used Rhino to create binding sides (4 sides and a flat base) to form a closed space then used RhinoResurf for the point cloud. My problem is how to convert to 3D solid. I have tried to export as STL (to may be solidworks) but keeps telling me its not possible (Warning: The STL file you are saving is not adequate for creating rapid prototype parts).
Please any ideas about the right procedure would be appreciated.

Thanks

Use the ShowEdges command to show “naked edges.” This will show you where your model is not closed. Repairing those places should help.