As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, CREW RECEIVED A FLAP ASYMMETRY MESSAGE DURING FLAP RETRACTION FROM 10 DEG TO 0 DEG. MAINTENANCE FOUND THE RIGHT-OUTBOARD FLAP ACTUATOR TO HAVE THE SMALL SHAFT THAT DRIVES THE ASYMMETRY SWITCH SHEARED. NO INDICATION WHY SHAFT SHEARED, SINCE ROTARY SWITCH SEEMS TO OPERATE OK. ACTUATOR AND SWITCH WAS REPLACED.