As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON APPROACH, THE TWO MLGS FAILED TO EXTEND UPON GEAR DOWN SELECTION AND THE CREW RECEIVED A "GEAR DISAGREE" WARNING MESSAGE. THE FLIGHT CREW EXECUTED A GO AROUND, LOWERED THE GEARS USING THE ALTERNATE HANDLE AND LANDED WITHOUT FURTHER INCIDENT. THE MLG SELECTOR VALVE WAS REPLACED, TESTED BY MAINTENANCE AND THE ACFT WAS RELEASED FOR SERVICE.