As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO THE FIELD FOR A LANDING GEAR AIR GROUND FAIL MESSAGE ON EICAS WHICH PREVENTED THE GEAR FROM BEING RETRACTED. THE AIRCRAFT ALSO EXPERIENCED A DUAL REVERSER DISAGREE AT 2500 FEET. MAINTENANCE IS CURRENTLY TROUBLESHOOTING. MX REPLACED LANDING GEAR ELECTRONIC CONTROL UNIT.