As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF ROLL APPROX AT 50 KNOTS WE GET A MASTER WARNING WITH A CONFIG GEAR EICAS MESSAGE. TAKE OFF DISCONTINUED. PERFORMED PSEU TEST PRI ALT GEAR SYSTEMS PASS. DEFERRED BODY GEAR STEERING IAW MEL 32-53-01. CAT C DDG COMPLIED WITH MDDR 128957.