As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT ABORTED THE TAKE-OFF AFTER THE CREW RECEIVED A DOOR WARNING FOR THE AFT CARGO DOOR. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE AFT CARGO DOOR HANDLE POPPED OUT. THE HANDLE WAS SECURED AND THE OPERATIONAL CHECKS WERE GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.