back plate not showing in background

[vanderloo]

Can someone give me some guidance on why, when I hit alt+B and select use file for background and choose a back plate that came with my HDRI image. It doesn't show in renders?
If I go into environment and use map, and add the same back plate it shows up fine. I just can't figure out why it wouldn't show by loading it as a background using alt+B.
Especially since it is showing in the viewport.
I'm in max 2106, VRay 3.2

[RotemS]

Everything is as it should be.

You're only loading it to the viewport background, that's what the alt+B dialog does. If you want it in render, you have to set it up in the environment panel, which you seem to be doing.

If you want to see it in both, set it up in the environment, and in the viewport background dialog select to use the environment as a background.