As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT MAIN LANDING GEAR UNSAFE LIGHT ILLUMINATED AFTER GEAR RETRACTION. CREW DECLARED AN EMERGENCY AND FLIGHT WAS RETURNED TO DTW. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND RIGHT GEAR DOOR ROLLER OUT OF RIG. RIGGED DOOR ROLLER. OPERATIONAL CHECK NORMAL ON GEAR SWING. AIRCRAFT RETURNED TO SERVICE.