As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RAMPER ADVISES UNABLE TO OPEN THE AFT PASSENGER DOOR. DOOR IS JAMMED IN ITS CURRENT POSITION. UNABLE TO MOVE. APPEARS OFF TRACK. REMOVED FROM SERVICE. FREED AFT PASSENGER DOOR. FOUND DOOR OUT OF SEQUENCE. RESET AFT PAX DOOR IAW Q400 SPGRG 52-01-01. DOOR OPENS AND CLOSES AS REQUIRED. NO FURTHER DEFECTS. RETURNED TO SERVICE. NO PARTS REPLACED.