Unable to get object metadata from S3. Check object key, region and/or access permissions in aws Rekognition

I had the same problem. What I did to fix it was to rearrange my bucket and the folders. Make sure that your image is directly in your bucket and not in a folder in your bucket. Also double check that the name of the images are correct and that everything is on point.

Check if the S3 and Image Rekognition is in the same region, I know, it's not nice or documented (I guess), but this guys are talking about it here and here