title: Prestashop 1.7.7. Error When Proceed to Checkout
body: <p>Like I explain at the title this issue it's related with the checkout of prestashop version 1.7.7.0.</p>
  <p>When I add I product to the cart, and then I press the button to proceed to the checkout I have this issue:</p>
  <pre><code>[21-Jun-2021 22:39:57 Europe/Madrid] PHP Fatal error:  Uncaught Error: Call to undefined method Cart::checkAllProductsAreStillAvailableInThisState() in /home/public_html/classes/checkout/CheckoutPaymentStep.php:48
  Stack trace:
  #0 /home/public_html/classes/checkout/CheckoutProcess.php(59): CheckoutPaymentStepCore-&gt;handleRequest(Array)
  #1 /home/public_html/controllers/front/OrderController.php(278): CheckoutProcessCore-&gt;handleRequest(Array)
  #2 /home/public_html/classes/controller/Controller.php(306): OrderControllerCore-&gt;initContent()
  #3 /home/public_html/classes/Dispatcher.php(518): ControllerCore-&gt;run()
  #4 /home/public_html/index.php(28): DispatcherCore-&gt;dispatch()
  #5 {main}
    thrown in /home/public_html/classes/checkout/CheckoutPaymentStep.php on line 48
  </code></pre>
  <p>I have made some test:</p>
  <ul>
  <li>Disable all the modules and have only to the native ones of Prestashop.</li>
  <li>Tried with a clean install and always i have the same problem.</li>
  <li>No matters if it's the default theme or the bought one.</li>
  <li>Delete the cache of prestashop...</li>
  </ul>
  <p>Clearly i'm desesperate with this problem... Any help will be so apreciate.</p>