As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5640, IAH TO LIT. WHILE CLIMBING THROUGH 23,000FT THE FLIGHT CREW RECEIVED A R REV UNLOCKED EICAS MESSAGE. THE EMERGENCY ACTION ITEMS WERE RUN AND THE RELEVANT CHECKLISTS WERE COMPLETED. THE REVERSER WAS THEN STOWED, BUT THE R REV UNLOCKED MESSAGE REMAINED ON EICAS. THE AIRCRAFT RETURNED TO IAH AND LANDED WITHOUT INCIDENT. MAINTENANCE COMPLIED WITH THE MEL PROCEDURES FOR THE REVERSER AND RELEASED THE AIRCRAFT TO SERVICE.