As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 122 - EMERGENCY LANDING - INBOUND TO MKE, APPROXIMATELY 40 MINUTES FROM LANDING, CREW RECEIVED A YELLOW HYDRAULIC SYSTEM FAILURE MESSAGE. CAPTAIN DECLARED AN EMERGENCY, AIRCRAFT LANDED AND TAXIED TO GATE WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE YELLOW HYDRAULIC ACCUMULATOR PER MM 29-13-42-400-001. OPERATIONAL AND LEAK CHECKED GOOD.