As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CENTER HYDRAULIC QUANTITY EICAS MESSAGE DISPLAYED INDICATION. AN IN FLIGHT EMERGENCY WAS DECLARED. THE AIRCRAFT LANDED SAFELY WITH NO OTHER PROBLEMS. AIRCRAFT WAS THEN GROUNDED BY MAINTENANCE. A HYDRAULIC LEAK WAS FOUND ON THE CENTER FLAP/SLAT SHUT OFF VALVE MODULE. THE VALVE WAS REPLACED IAW AMM 27-51-48. THE AIRCRAFT WAS RETURNED TO SERVICE.