As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER LANDING GEAR RETRACTED, CREW NOTED LANDING GEAR CAUTION LIGHT ILLUMINATED. THE CREW PERFORMED AN ATB TO DEPARTURE AIRPORT. MAINTENANCE FOUND NLG DOOR CLOSED SENSOR OPEN CIRCUIT. SENSOR REPLACED AND THE AIRCRAFT WAS RETURNED TO SERVICE. (TC# 20190704015)