As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE WARNING MESSAGE LANDING GEAR WOULD NOT EXTEND HAD TO MANUALLY EXTEND THE GEAR STEERING INOP CAUTION AS WELL. RESET UNSUCCESSFUL / REMOVED AND REPLACED LANDING’GEAR SELECTOR VALVE IAW CRJ 900 AMM 32-32-10-000/400-801. OPS CHECK GOOD GEAR SWING GOOD.