As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, REVERSER ISOLATION VALVE STATUS MESSAGE AND REVERSER ISOLATION WARNING LIGHT ILLUMINATED. AIRCRAFT RETURNED TO DEPARTURE AIRPORT, NO FUEL WAS DUMPED AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE DEACTIVATED AND STOWED THRUST REVERSER. THRUST REVERSER WAS PLACED ON MEL AND AIRCRAFT RETURNED TO SERVICE.