When I open a page for a new product the Shortcode URL is already present. I write the product name in H1. I insert a preview image of the product. I enter the price. At the bottom right I paste the URL of the product pdf file and on the left the product title. I update, view, purchase, save in the cart, but on the left it says restore the previous cart, I don’t click on it, accept the terms and conditions and privacy policy, and complete the payment with purchase. A 404 “Page Not Found” page opens. But, I receive the purchase receipt with the file to download, and an email of a new sale from the site.

Last thing. Even if you haven’t pasted the Shortcode URL for the purchase button, you can see it online and click.
Could someone kindly tell me what I need to do to make my Easy Digital Download work properly?
Thank you
Santino