As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE MAIN DOOR SEAL LIGHT CAME ON AND THE MAIN DOOR SEAL DEFLATED. TROUBLESHOOTING WAS PERFORMED ON THE GROUND BY PRESSURIZING THE MAIN DOOR SEAL AIR SYSTEM. WHEN AIR WAS REMOVED FROM THE DOOR SEAL SYS, THE DOOR SEAL DEFLATED IN LESS THAN A MINUTE INDICATING A FAILED CHECK VALVE. THE CHECK VALVE IN THE DOOR SEAL AIR INLET LINE WAS REPLACED. THE DOOR SEAL NOW STAYS INFLATED FOR MORE THAN 10 MINUTES WITH AIR REMOVED. FLIGHT OPS TEST WAS NORMAL.