As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN CARGO DOOR WARNING LIGHT ILLUMINATED DURING CLIMB THROUGH FL290. CABIN WAS PRESSURIZED NORMALLY. DEPRESSURIZED & DESCENDED TO 10,000 FEET. LIGHT EXTINGUISHED. INDICATION SWITCHES GAP ADJUSTED TO TOLERANCE. WORN DOOR MECHANISM CAUSING SWITCH GAP TO FALL OUT OF TOLERANCE.