As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT DECK DOOR WILL NOT OPEN FROM INSIDE. THE UPPER BAYONETE WILL NOT RETRACT FAR ENOUGH WHEN TURNING THE HANDLE. DOOR CAN ONLY OPEN USING THE LOCK/UNLOCK SWITCH, THUS A TWO PERSON OPERATION ONLY. MAINTENANCE REPLACED UPPER DOOR LATCH PER AMM 52-51-21 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.