Fatal error on order cancellation – missing method in Subscription plugin

Hello YITH support team,

I’m facing a critical fatal error with YITH WooCommerce Subscription whenever an order is cancelled. When changing the status from Completed to Cancelled, WordPress crashes with the following error:

PHP Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class YWSBS_Subscription_Order does not have a method "cancel_subscriptions" in /wp-includes/class-wp-hook.php on line 326

This indicates that your plugin registers the following invalid hook:
add_action('woocommerce_order_status_cancelled', ['YWSBS_Subscription_Order', 'cancel_subscriptions']);
However, the class YWSBS_Subscription_Order does not implement the cancel_subscriptions() method, which causes a TypeError and a complete backend crash during order cancellation.

To keep my site stable, I had to create a temporary workaround that removes this faulty hook before execution. The issue is easily reproducible on any WooCommerce order with a subscription product.

Environment:

• WordPress 6.7.1
• WooCommerce (latest)
• YITH WooCommerce Subscription (latest)
• PHP 8.3
• Theme: Themify Builder-based

Expected behavior: cancelling an order should deactivate the related subscription gracefully, without triggering a fatal error.

Please escalate this issue to your development team — it’s a blocking problem under PHP 8+. I can provide admin access or detailed logs if needed.

Thank you,
Frédéric Le Guen
Founder – Excel-Exercice.com