As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ROTATION THE CREW RECEIVED A LANDING GEAR AIR/GROUND FAIL MESSAGE FOLLOWED BY A REVERSE DISAGREE MESSAGE. THE CREW FOLLOWED THE QRH AND RETURNED TO FIELD. THE AIRCRAFT LANDED WITHOUT INCIDENT AND THE AIR/GROUND MESSAGE CLEARED ON LANDING. MAINTENANCE FOUND THE NOSE LANDING GEAR WEIGHT ON WHEELS PROX SWITCH DAMAGED. THE PROX SWITCH WAS REPLACED IAW AMM 32-63-02-4 AND A GEAR RETRACTION WAS PERFORMED WITH NO DEFECTS NOTED.