As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN OPERATED DURING FLIGHT 3555, 'LE SLAT DISAGREE' MESSAGE DISPLAYED. THE LE SLAT COULD NOT BE EXTENDED. FOUND THE ROTARY ACTUATOR AT THE RT WING TIP HAD DEFECT. AS MAINTENANCE HAD NO REPAIR PARTS, THE FLIGHT WAS CANCELLED. OPERATOR SENT MAINTENANCE PEOPLE TO REPAIR THE FAULT. CHANGED THE ROTARY ACTUATOR, CK OK.