When the buyer must go to checkout and if the buyer does not choose whether he will just buy and without creating themselves a account or just want to buy as a guest. If they do not enter their shipping information name and address and just checking them self out to paypal.
Then buyer will see this error and buyer can dont do nothing. You can not press anything as you can see on the displayed options shown in the picture
Then you have to update the page and fill in the fields or return back to Billing Address section and write all information. I’ve just checked the Checkout form in Chrome browser and repeated the checkout process successfully.