I'm checked in for AC884 tomorrow evening for YUL-GVA. Have seats assigned in the J cabin. Online check-in didn't issue a boarding pass, and says to pick it up at the airport. I've not seen that before, but I don't travel as often as most. Am I in for a problem? There is still a seat number assigned in my booking. The e-mail boarding pass received, looks like a boarding pass, but specifically says it is "Not a valid boarding pass".

Any insight or advice?