As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WILL NOT PRESSURIZE ON DEPARTURE. PERFORMED WALK AROUND & FOUND THE AFT CARGO DOOR NOT SEATED. CLOSED AFT CARGO DOOR & PERFORMED OPERATIONAL CHECK OF THE CABIN PRESSURIZATION SYS IAW AMM 21-31-00. OPERATIONS CHECK IS GOOD AT THIS TIME.