Unable to generate a prestashop error 500 invoice - symfony

Question

I am coming to you because I have a problem with prestashop, when I try to generate an invoice after purchase, the site sends me back to an error 500 and I cannot recover my invoice, what to do?
Error returned to me by the site in production mode:
Oops! An Error Occurred
The server returned a "500 Internal Server Error".
Something is broken. Please let us know what you were doing when Ibis error occurred. We will fur it as soon as possible. Sorry for any inconvenience caused.
Error returned to me by the site in developement mode:
ClassNotFoundException
Attempted to load class "DpTools" from the global namespace. Did you forget a "use" statement?
in override/classes/order/OrderInvolce.php (line 52)
$products = parent::getProducts($products, $selected_products, $selected_pty);
if (is_array($products)))
{
foreach ($products as $index => $product)
{
if ((int)$product['id_product'] == DpTools::getSpecialProduct())//<< error Line
unset($products[$index])
}
}
return $products;
}

Answer 1

This error means that your Prestashop OrderInvoice.php file had been overriden by a module and it's not the original one.
Try inspecting
override/classes/order/OrderInvoice.php
in your FTP - You should be able to find the module name that is causing the override in a comment.
Then try to disable or uninstall that module and see if the issue is still there.
Otherwise you can try to rename that override/classes/order/OrderInvoice.php and empty the cache so the original one will be used , this will probably interfere with that module functionalities , though.