Hello guys,

I built my first box, when I add the selected products to the checkout I get the message:

Please wait a moment while we prepare your custom gift box!

But admin-ajax is failing with error 500 and this PHP error is generated:

Uncaught TypeError: trim(): Argument #1 ($string) must be of type string, WC_Product_Attribute given in /var/www/html/site/public_html/wp-content/plugins/woocommerce/includes/class-wc-cart.php:993
Stack trace:
#0 /var/www/html/site/public_html/wp-content/plugins/woocommerce/includes/class-wc-cart.php(993): trim(Object(WC_Product_Attribute))
#1 /var/www/html/site/public_html/wp-content/plugins/woocommerce/includes/class-wc-cart.php(1148): WC_Cart->generate_cart_id(227452, 0, Array, Array)
#2 /var/www/html/site/public_html/wp-content/plugins/doko-box-builder/public/class-hs-doko-public.php(524): WC_Cart->add_to_cart(227452, '1', 0, Array, Array)
#3 /var/www/html/site/public_html/wp-includes/class-wp-hook.php(324): Hs_Doko_Public->add_to_cart('')
#4 /var/www/html/site/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#5 /var/www/html/site/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#6 /var/www/html/site/public_html/wp-admin/admin-ajax.php(188): do_action('wp_ajax_doko_wc...')
#7 {main}
  thrown

Is this plugin still working on latest WC versions?

Thanks
Daniele