Ok, honestly. How the hell are you supposed to post pictures on this site. I've tried 100s of crop settings and all of them just gave me the 403 error. Is there some trick I'm not getting or does this site just really hate iPhones
when you screenshot in an iphone the picture is usually very large (often more than 3 mb) and this website doesn't pictures that big, try putting them in a computer and change their type to .jpg or .png. had the same problem and it worked for me...