As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER GEAR RETRACTION (6 TO 10 SECONDS) RECIEVED GEAR DISAGREE WARNING WITH NOSE DOOR WARNING WITH GEAR LEVER IN UP POSITION. RAN QRH,MESSAGE WENT AWAY, GEAR DOWN AND LOCKED. CREW PERFORMED AN AIR RETURN TO ORD. ON POST FLIGHT, FO FOUND HYD FLUID IN NOSE GEAR BAY. INSP AND FOUND NLG WOFFW2 AND OLEO CENTERED/EXTENDED HARNESS CRUSHED AT LOWER PROX SENSOR.