As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF ROLL IN STL ON RW 12L, EICAS MESSAGE "DFDR FAIL" APPEARED AT 60 KNOTS. THE TAKEOFF WAS ABORTED. WHEN THE FLIGHT RETURNED TO THE GATE, MAINTENANCE DEFERRED THE ITEM AND THE FLIGHT THEN CONTINUED AS NORMAL. ON THE NEXT DAY IN STL, MAINTENANCE CLEARED THE MEL BY REPLACING THE DFDR. ALL OPERATIONAL CHECKS WERE GOOD AND THE MEL WAS THEN CLEARED.