As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED LEFT MAIN GEAR DISAGREE RED MESSAGE ON TAKEOFF FROM CLT. CREW RETURNED TO CLT AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND TROUBLESHOT LANDING GEAR SYSTEM, TIGHTENED LOOSE TARGET ON LEFT MAIN LANDING GEAR UPLOCK AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT WAS RELEASED FOR SERVICE.