Ok, you have h.264 in a .mov container. Apple does not really support h.264 movies in a QuickTime container any more and it never was a really good idea. Try changing the extension to .mp4 and see if AE will recognize it. Sometimes that works.
If it does not work then you'll have to transcode the footage to a better format. I would not recommend re-encoding the move as h.264 in any container because the quality of recompressed MPEG files goes down very quickly. Pick a suitable Mezzanine format for your DI.
Mezzanine format means visually lossless frame based and DI means digital intermediate. You can learn a little more about those terms with Google..