As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A RED GEAR DISAGREE MASTER WARNING IN FLIGHT ON APPROACH TO CLT. CREW COMPLIED WITH QRH, USED MANUAL GEAR EXTENSION AND LANDED IN CLT WITHOUT FURTHER INCIDENT. MAINTENANCE TROUBLESHOT THE AIRCRAFT, REMOVED AND REPLACED THE MAIN LANDING GEAR SELECTOR VALVE AND PERFORMED CHECKS USING THE AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT WAS RELEASED FOR SERVICE.