As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF AT 1000 FT, CREW RECEIVED A REVERSER UNLOCK MESSAGE. CREW LEVELED OFF AT 3000, RAN QRH, AND SHUT THE RH ENGINE DOWN. AN EMERGENCY WAS DECLARED AND THEY RETURNED TO DEPARTURE AND LANDED WITHOUT INCIDENT. R/R RED CORE-COWL HARNESS RH ENGINE IAW CRJ 200 AMM 71-50-00-000/400-804. REACTIVATED RH TR IAW CRJ200 AMM 78-30-00-440-802. CW OPS CHECK OF RH ENG TR IAW CRJ 200 PPGRM 71-00-00-710-806. NO DISCREPANCIES OBSERVED.