Hi, Joelly3D,
I inestigated the problem with your scene. It’s a combination of few things: the geometry that is invisible to camera it still present in the scene and rays have to be tracked through it. In the invisible geoemtry there is a ray trap: two planes that are very close to each other. (acting as duplicated faces) This causes some precision problems and some rays get stuck there(if embree is used to trace rays). The default vray ray tracer manages to jump over the trap, because it uses different computation.
This leads to two possible solutions to render the scene:
1. Do not use embree
2. Remove one of the overlaping planes in the invisible object