As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 3338 - CLE-PVD - DURING CRUISE AT FL270, "RT REV UNLOCK" CAUTION MESSAGE APPEARED. RAN THE QRH WHILE STARTING DESCENT. DECLARED AN EMERGENCY WITH ATC, LANDED WITH NO FURTHER INDICATIONS. MAINTENANCE DEFERRED THE THRUST REVERSER.