As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF RECEIVED RT MAIN GEAR DISAGREE MESSAGE. COMPLIED WITH QRH AND RETURNED TO DEPARTURE. EMERGENCY DECLARED. FOUND RT MAIN UPLOCK PROXIMITY SENSOR OUT OF ADJUSTMENT. PERFORMED ADJUSTMENT OF RT MAIN UPLOCK PROXIMITY SENSOR IAW AMM 32-32-05. PERFORMED OPS TEST OF GEAR EXTENTION RETRACTION SYS IAW AMM 32-30-00. NO DEFECTS NOTED.