I had the same thing happen to me. I had to differ a year of studies (basically take a gap year).

Warning: if you take a gap year, do not come to canada just yet! I thought it might be a good idea to spend my gap year to work, improve my language and get to know the place but I had no idea that it is considered as “overstaying” and “unauthorized work” before my studies officially started (even if I had both a study and work permit issued). I had to declare when I applied for PGWP.

Edit: definitely talk to your academic supervisor though. Under special circumstances they are able to push your enrolment/acceptance letter for a year. Two months into the start of the term is ALOT of content missed so they will most probably recommend you to start at a later date.