As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB FROM TAKEOFF, CREW RECEIVED AN AIR/GROUND FAIL MESSAGE ON THE EICAS AND GEAR WOULD NOT RETRACT. MAINTENANCE INSPECTED AND FOUND THAT THE LT MLG WOW PROXIMITY SENSOR REQUIRED ADJUSTMENT. ADJUSTMENT WAS MADE AND LANDING GEAR SYSTEM, OPS CHECKED GOOD.