As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AMBER CABIN ALT EICAS MESSAGE ILLUMINATED AT FL 450. CABIN WOULD NOT MAINTAIN A NORMAL CAB ALT IN MAN PRESS AND FULL DOWN RATE. CONDUCTED OP CHECKS OF PRESSURIZATION SYSTEM, IASCS, AND PROVIDED DOWNLOADS FOR EVALUATION TO BOMBARDIER. MAINTENANCE PERFORMED IAW AMM TASK 21-31-01-710-801. NO FAULTS FOUND AT THIS TIME