As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED, "ON DEPARTURE, DURING GEAR RETRACTION RECEIVED LANDING GEAR DISAGREEMENT MESSAGE AND LANDING GEAR DID NOT RETRACT. (AIR RETURNED TO EWR)"....MAINTENANCE REMOVED AND REPLACED LANDING GEAR CONTROL LEVER IAW EMB145 MM NR 32-32-02. OPS. AND GEAR (RETRACTION CHECK) SWING GOOD. AIRCRAFT RETURNED TO SERVICE.