Displaying Light Beams

I use IRender nXt with Sketchup 2015, to add spot lights, Point lights, however the light effect/beam is not showing after rendering. Please help. Thanks 

The beams on Spot Lights never appear in the rendering. The only beams that show up in the rendering are the ones with the "Beam" Lights.

As you can see in the image below, both spot light beams and "Beam" beams appear in SketchUp, but only the beams in the special "Beam Lights" appear in the rendering.

See: Visible Light Paths