Warning message

This morning a customer sent me a screenshot of an error message they received when trying to purchase a gift card on our shop: Warning: sizeof(): Parameter must be an array or an object the implements Countable in public_html/wp-content/woocommerce-product-addons/includes/fields/class-product-addon-field-custom.php on line 19

I searched for this error message but haven’t seen it in relationship to this plugin. Any ideas?

Thanks!

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