As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT RETRACTION WE GOT A FLAPS FAIL FLAPS STAYED AT 20* RAN THE FLAPS FAIL CK LIST & RETURNED FOR LANDING AT KSJC. MX C/A: PERFORMED FLAPS OPS CHECK AND GVI CHECK REF CHALLENGER 605 AMM 27-51-04-710-801. OPS CHECK GOOD. FLAPS MOVE UP AND DOWN SMOOTHLY. FOUND NO DEFECTS AT THIS TIME.