As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN ALT CAUTION MSG, AT FLT LEVEL 360, CABIN ALT WENT TO 9000FLT / INSPECTED THE #2 SAFETY VALVE AND FOUND LOOSE INSULATION STUCK BETWEEN THE DIAPHRAGM AND IT€™S SEAT. REMOVED INSULATION AND PERFORMED A FUNCTIONAL TEST OF THE SAFETY VALVE IAW CRJ 700 AMM 21-32-03-720-802-A01. PERFORMED A PRESSURIZATION CHECK OF THE AIRCRAFT IAW CRJ 700 AMM 21-31-00-910-801-A01-PSA. OPS CHECKS GOOD.