Fatal Error Php 8.xx

Hello, I hope you’re fine !

I’m working on a website with WordPress 6.1.1 and Php 8.1

When adding 2 products which are therefore assigned to a discount rule, I’ve got this Fatal error.

It’s seem that your code is not fully compatible.

It seems that problem is far similar to : https://www.ads-software.com/support/topic/product-price-error-on-php8-0/

Could you see what’s going on please?

 Fatal error: Uncaught Error: in_array(): Argument #2 ($haystack) must be of type array, null given
in /home2/xxxxxx/mywebsite.io/wp-content/plugins/woo-advanced-discounts/includes/class-wad-discount.php on line 546

Pile d’appel :

in_array()
wp-content/plugins/woo-advanced-discounts/includes/class-wad-discount.php:546
WAD_Discount::get_total_cart_discount()
wp-content/plugins/woo-advanced-discounts/includes/class-wad-discount.php:589
WAD_Discount::woocommerce_custom_surcharge()
wp-includes/class-wp-hook.php:308
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:332
WP_Hook::do_action()
wp-includes/plugin.php:517
do_action()
wp-content/plugins/woocommerce/includes/class-wc-cart.php:1888
WC_Cart::calculate_fees()
wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php:272
WC_Cart_Totals::get_fees_from_cart()
wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php:833
WC_Cart_Totals::calculate_fee_totals()
wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php:145
WC_Cart_Totals::calculate()
wp-content/plugins/woocommerce/includes/class-wc-cart-totals.php:134
WC_Cart_Totals::__construct()
wp-content/plugins/woocommerce/includes/class-wc-cart.php:1401
WC_Cart::calculate_totals()
wp-includes/class-wp-hook.php:306
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:332
WP_Hook::do_action()
wp-includes/plugin.php:517
do_action()
wp-content/plugins/woocommerce/includes/class-wc-cart.php:1279
WC_Cart::add_to_cart()
wp-content/plugins/woocommerce/includes/class-wc-form-handler.php:824
WC_Form_Handler::add_to_cart_handler_simple()
wp-content/plugins/woocommerce/includes/class-wc-form-handler.php:796
WC_Form_Handler::add_to_cart_action()
wp-includes/class-wp-hook.php:308
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:332
WP_Hook::do_action()
wp-includes/plugin.php:517
do_action()
wp-settings.php:639
require_once()
wp-config.php:112
require_once()
wp-load.php:50
require_once()
wp-blog-header.php:13
require()
index.php:17

I really need your plugin to work, I’m taking over a client site whose entire business logic is based on your plugin.

Thanks a lot,
Renaud