Hi Jean-Paul - it looks like Rhino is having a problem generating the render mesh on that object.

Can you please post the 3DM model file, or e-mail it to me at moi@moi3d.com if you want to keep it private? That will let me take a look at the model to see if there is something wrong in the model or if it is one of the cases that Rhino's mesher does not like to handle.

For the moment to make a rendering, you can export from MoI to OBJ format (probably use Output: Quads & Triangles option) and bring that into Rhino, which should then render fine since it will already be a mesh.

- Michael