This issue has me really stumped.
I have tried multiple files, creating simple ones from scratch or importing them from AI and the result is the same. When I try to open my work in the Picture Viewer, use Interactive Renderer or try to open my work in Ae - the image is completely black. It is as if the lights do not work.
I checked the cameras, render settings, etc. No luck...
Without seeing your scene or at least some screenshots, we'd just be making wild guesses. Also, we don't know what version of AE you're running, what OS, what your system specs are, etc.
Are you following the workflow in these resources: details of CINEMA 4D integration with After Effects ?
AI files? Do you actually extrude/ loft/ sweep them? Are the prepared suitably? you need to be much more specific.