As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB DOOR UNLOCKED ANNUNCIATION CAME ON. CREW FOLLOWED EMER CHECKLIST PROCEDURES, DECLARED AN EMER LANDING & DIVERTED. TROUBLE SHOT THE DISCREPANCY TO A BAD MAIN ENTRY DOOR SEAL. THE MAIN ENTRY DOOR SEAL WAS DEFERRED IAW THE MEL. ACFT WAS MOVED FOR SEAL REPLACEMENT. MAIN ENTRY DOOR SEAL WAS REPLACED. OPERATIONS CHECK PERFORMED & THE ACFT WAS RETURNED TO SERVICE.