As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED CARGO DOOR CAUTION MESSAGE IN FLIGHT. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. HANDLE WAS CONFIRMED OPEN BY GROUND PERSONNEL. MAINTENANCE CLOSED CARGO DOOR HANDLE AND INSPECTED CARGO DOOR USING AIRCRAFT MAINTENANCE MANUALS. NO DEFECT FOUND. AIRCRAFT RELEASED FOR SERVICE.