As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT RETURNED TO NARITA DUE TO FLAP PROBLEM.CREW HAD EICAS MESSAGE FLAPS PRIMARY, AND RT MIDSPAN INDICATION WENT TO RED, EACH SPEED INCREASE. THE CREW SENSED NO CONTROL PROBLEMS. NRTMM REPLACED THE NR 3 RT LE SLAT DRIVE UNIT. NO FURTHER HITS HAVE BEEN REPORTED.