If you open the composition it created, do you see anything?
What sort of artwork is in your Illustrator file?
What exact version of Illustrator are you using? What exact version of After Effects are you using? (I see from the blue color that you're at least on version 13.1.0.)
If I open the composition, nothing is there. Just black.
The artwork is simple vector shapes. Really simple ones. Image attached.
I'm using all up to date CC versions of both Illustrator and AE.
The individual layers say they're each 1.6 megs, that's a lot more than a single pixel.
Debugging this can be a drag but go back to Il and try saving the file as a copy but with some different settings for the PDF enabler and other stuff. Try saving a couple of copies with just one layer at a time. Try importing the original file with different options.
But only try one of these changes at a time.
Since it hasn't been eliminated yet, let's do so: the Illustrator artwork isn't black, and you're trying to see it over a black AE background?, is it
Is all the artwork inside the art board? Do you have more than one art board?
I know I'm very late to the party, but I recently had this problem and figured it out!
For anyone with the similar problem:
Your AI file isn't saved as pdf compatible. Save it again and make sure the box is checked. Fixed it for me!