As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CARGO DOOR CAUTION MESSAGE DURNG FLIGHT, RAMP INFORMED HANDLE WAS OUT ON RETURN TO GATE. CABIN WILL NOT PRESSURIZE, SECURED THE AFT CARGO DOOR. PRESSURIZED ACFT TO 3.0 PSI AND HELD FOR 10 MINS. NO LEAKS FOUND INSIDE ACFT OR BY CARGO DOOR. DOORS STAYED SECURE & OPS TESTED GOOD IAW AMM 21-31-00.