As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 5122. INFLIGHT LT REVERSE UNLOCK MSG. DURING CRUISE FLIGHT, LEFT ENGINE REVERSE UNLOCK CAUTION MESSAGE APPEARED. [EMERGENCY DECLARED AND HAD EMERGENCY VEHICLES ON STANDBY AS A PRECAUTION -- ENROUTE TO CVG A/C DIVERTED TO TRI DUE TO MTC] ( THRUST REVERSER SYSTEMS )