As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED GEAR DISAGREE RED MESSAGE UPON GEAR-UP SELECTION AFTER TAKEOFF. CREW RAN QRH, RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT LANDING GEAR SYSTEM, REMOVED AND REPLACED MAIN LANDING GEAR SELECTOR VALVE AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT RELEASED FOR SERVICE.