solid models not appearing

Hello,

  I am trying to add solid spheres to an existing model which has lines and point clouds in it. When I add a sphere it disappears. I have tried all of the display styles but cannot see any solid models. Perhaps there is a setting that I need to change, or turn on/off and I'm just missing it? I've also tried this same thing in both Open Cities and Descarte hoping one would allow it to work, but same result with both programs.