As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN-FLIGHT WITH RIGHT PACK SELECTED ON AND RIGHT 10TH STAGE BLEED SELECTED ON, RIGHT PACK INOP ECS PAGE SHOWED RT PACK AND 10TH STAGE VALVE CLOSED. CABIN TEMP TOO HIGH, ACFT RETURNED TO DEN. MAINTENANCE REPLACED RIGHT 10TH STAGE BLEED VALVE.