As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LEVEL OFF AND APPROACHING OCEANIC AIRSPACE NR 4 L/E FLAP TRANSIT LIGHT (AMBER) BLINKED AT LEAST 3 TIMES AT FL350 AMD 0.79 MACH. ACFT GROUNDED. DIVERSION TIME - 45 MINS. R & R NR 4 L/E SLAT RETRACT PROXIMITY SENSOR REF 27-88-11. PERFORMED L/E PROXIMITY SENSOR TEST, TESTED NORMAL REF MM 27-88-11.