As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER TAKEOFF, LANDING GEAR DID NOT RETRACT. INDICATION SHOWED 3 GREENS AND 3 REDS. AFTER EMERGENCY CHECKLIST WAS COMPLETED THE DECISION FOR RE-LANDING WAS MADE. CABIN PAX AND STATION WERE INFORMED AND SUCCESSFUL RELANDING PERFORMED. FOUND NOSE WHEEL CENTER SENSOR FAULT AND SENSOR REPLACED. (TC NR 20061020006)