JetPack causing error – post-template.php line 284

When I add a new page I get this error at the top:
Warning: count(): Parameter must be an array or an object that implements Countable in (I took this part of the address out)\backyardpollinator.com\wp-includes\post-template.php on line 284

It doesn’t matter what theme I have installed.
I do have woocommerce installed, and this error even happens with their default welcome page.
This site is a store site and only has one page (the one I’m trying to create) other than the woocommerce default pages for which the error doesn’t happen.

{All other pages from the menu go back to the sister site on the .ca domain…. this one is on the .com domain.}

Those lines on 284 of the post-template.php are
if ( $page > count( $pages ) ) // if the requested page doesn’t exist
$page = count( $pages ); // give them the highest numbered page that DOES exist

I sequentially turned off plugins and found that it is Jet pack that is causing the problem, so I’ve had to disable it. So with it disabled the error is not showing.
Can someone help with this. I can re-enable Jet pack so you can see the error on the product page if you like.

The page I need help with: [log in to see the link]