Files mising from eShop for WordPress after updating to WordPress 4.5

After updating to WordPress 4.5 three of the six pages provided with eShop for WordPress disappeared, including the Checkout page. This means the shop is not working because ‘Proceed to checkout’ leads to a page saying the shopping cart is empty when it’s not, so the purchase cannot proceed. To my alarm, I find that this plugin no longer exists, so does anyone know how i can restore these files? Or download another version of the plugin so I can reinstall it which, I assume, would restore the files? I’m trying to find the missing files through my web hosting service but I think their oldest backup of the database will be after this happened. My website is globalspiritualstudies.com