As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH AFTER LANDING GEAR EXTENSION, RECEIVED L/G GEAR NOT DOWNLOCKED MESSAGE. ALL THREE LANDING GEAR INDICATION TRIANGLES WERE ILLUMINATED RED. CYCLED LANDING GEAR HANDLE AND ALL INDICATIONS WERE NORMAL. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE CLEANED ALL DOWNLOCK PROXIMITY SENSORS. OPERATIONAL CHECK OK.