As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE INBOUND CREW REPORTED AN "ACRID SMELL" AND "HAZE" IN THE CABIN. UPON ARRIVAL, MAINTENANCE FOUND THE APU WAS OVER-SERVICED AND THE OIL CAP WAS LEAKING. APU SERVICED TO CORRECT LEVEL AND OIL CAP REPLACED. A DUCT BURNOUT WAS SATISFACTORILY PERFORMED AND NO FURTHER SMELL WAS NOTED. THE AIRCRAFT HAS RETURNED TO SERVICE.