As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE FLIGHT NR 2356, THE CREW REPORTED A LANDING GEAR AIR/GND FAIL MESSAGE AFTER TAKEOFF AND GEAR RETRACTION. THE AIRCRAFT RETURNED TO CLE AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED AND REPLACED THE LEFT GEAR WOW PROXIMITY SENSOR. OPERATIONAL CHECKS WERE GOOD.