As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EWR---CO3418, CREW REPORTED, LANDING GEAR FAILED TO RETRACT AFTER TAKEOFF. EICAS MESSAGE LDG GEAR DISAGREE. MAINTENANCE REMOVED AND REPLACED LANDING GEAR CONTROL LEVER IAW EMB145 MM 32-32-00, AND PERFORMED SEVERAL LANDING GEAR EXTENSIONS AND RETRACTIONS IAW EMB145 MM 32-30-00. NO FURTHER FAULTS NOTED. AIRCRAFT RETURNED TO SERVICE.