It means what it says. You cannot pay because the seller did not specify shipping costs to Canada. It is further possible that the seller does not ship to Canada.
It is very important that a buyer checks the cost of shipping before bidding. If the seller does not want to ship to your country, you will get that message. If he is willing-- and to find out you should be using the Contact Seller link on the listing-- he can charge whatever he thinks is reasonable for the service.
Whatever that is, if you do not pay it, you can be hit with an Unpaid Item Strike, which will restrict your ability to bid on eBay in future.
So.
Contact the seller.
Ask that the shipping cost be added to the invoice .
Pay.
BTW, most US seller are content to ship by USPS International Letter Mail, which is fairly inexpensive and can take up to 4 lbs. However, many have a policy of adding Delivery Confirmation to their shipments. In the USA this costs about at quarter, but Delivery Confirmation on International shipments starts at $25. In future, ask first, bid later, when you know what you are going to pay.
