A Morningstar Avions de Transport Regional ATR-72-200, registration C-FTAR performing flight MAL-8069 from Montreal Mirabel,QC to Quebec City,QC (Canada) with 2 crew, was climbing through 12000 feet out of Montreal when the crew received an "EXCESS CABIN ALT" indication. The crew stopped the climb, declared PAN PAN, and descended the aircraft to 10,000 feet. The captain subsequently realized the cockpit document door was not completely closed and closed the door. The cabin pressure became normal again, the crew cancelled the PAN and continued to destination for a safe landing.
The Canadian TSB reported on Jun 4th 2020, that the pre-flight checklist was amended to double check the cockpit document door.