A new PHP critical error in the checkout

Hi – thanks for your update to v2.3.9 which fixed a previous PHP error in the checkout on the site which is preventing people completing it.

Unfortunately today we’ve started seeing a similar but different PHP error which is also preventing things from working. We can see from the stack trace that it’s related to this plugin. Here’s one example of many in our logs:

[27-Oct-2021 10:32:32 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_tax_class() on null in /wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php:225
Stack trace:
#0 /wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php(651): WC_Cart_Totals->get_items_from_cart()
#1 /wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php(143): WC_Cart_Totals->calculate_item_totals()
#2 /wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php(134): WC_Cart_Totals->calculate()
#3 /wp-content/plugins/woocommerce/includes/class-wc-cart.php(1398): WC_Cart_Totals->__construct(Object(WC_Cart))
#4 /wp-content/plugins/woo-discount-rules/v2/App/Helpers/Woocommerce.php(492): WC_Cart->calculate_totals()
#5 /wp-content/plugins/woo-discount-rules/v2/App/Helpers/Woocommerce.php(500): Wdr\App\Helpers\Woocommerce::calculateCartTotals()
#6 /home in /wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php on line 225

Please could you look into this as soon as possible?

Thanks!

Tim