As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE RED MESSAGE CAME ON AFTER TAKEOFF DURING GEAR RETRACTION. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED, PERFORMED FULL OIL AND NITROGEN SERVICE ON NOSE LANDING GEAR SHOCK STRUT AND PERFORMED CHECKS IAW AMM. AIRCRAFT RELEASED FOR SERVICE.