Just got stuck with this error while I'm trying to publish an app to app store. Sorry because i cant copy-paste the error code so I will post an image in my question.
Are you sure the 568h file is actually in PNG format? Also make sure that you provided support for iphone 5 for all your screens? Only adding
Defaultfirstname.lastname@example.org is not gaurantee for iphone 5 support. You have to check for framing of all your view for iphone 3.5" and 4" device.
You can do the framing by code or autoresizing that is other thing.
Kindly check out this link: Your binary is not optimized for iPhone 5