Put a background object in your C4D scene and see if it works then. (This is just a troubleshooting step.)
You C4D screenshot shows that you're looking at the editor window area that is outside of the render area. It's a common problem.
C4D allows you to see outside of the render region if your windows are scaled in an aspect ratio different from what your render settings are. (You can turn on options in your view attributes to block that area from view)
You can change your render settings, or, if things get a little more complicated, you can change your film offset settings in your camera to render the parts that are missing, so you can comp them in Ae.
The change I made to fix the problem was in Cineware, checking the Cinema 4D Multi-Pass box, and then changing the multi-pass from RGBA Image to Atmosphere.
Glad you got it.