As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF AFT CARGO DOOR WARNING LIGHT ILLUMINATED. RETURNED TO DEN WITH AFT CARGO DOOR LIGHT PROBLEM. DOORS CHECKED, FLIGHT DEPARTED WITH 92 PASSENGERS 1:05 LATE. FOUND AFT CARGO DOOR WARNING SWITCH TARGET LOOSE AND OUT OF POSITION. SECURED TARGET AND CHECKED DOOR WARNING OPERATION, REF MM 52-71-32. DOOR WARNING OPS CHECKS NORMAL.