VRay output_fileName seems doesn't work

Hi all

I'm trying to drive some VRay Render options via MaxScript, but I have some problem with output_fileName string.

here is my code:

vr = renderers.current
vr.output_on = true
vr.output_saveFile = true
vr.output_fileName = "D:\\test.jpg"
 

Run it but doesn't work. No files are generated.

Someone coud help me to understand how to use it?

Thanks,
David