As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 3276 - IAH-MCI - EN ROUTE AT FL310 -R REV UNLOCKED- MESSAGE APPEARED. REDUCED THRUST ON RIGHT ENGINE TO IDLE AND RAN QRH. DETERMINED REVERSER DID NOT DEPLOY. DECLARED AN EMERGENCY. APPROACH AND LANDING WERE UNEVENTFUL. MAINTENANCE DEFERRED THRUST REVERSER.