I got that error code and the line below it about how my "request was submitted" and that the the booking cancellation would have to be manually processed and would take up to 10 business days. I never received any kind of email but it did say to print that page for my records. Given the sh#tshow that must be the Aeroplan booking system these days I chose to call in when the reservations were still showing "ticketed" after about 8 days. Points are back in my account but I am still waiting for my tax and fee refunds to be processed.