ENVIRONMENT<\/p>\n\n\n\n
SYMPTOM ROOT CAUSE WooCommerce core still has I suspect WooCommerce 11 changed how those callbacks are registered (e.g. first-class callable \/ Closure instead of EVIDENCE<\/p>\n\n\n\n 1) PHP 8.3 fatal (zend.max_allowed_stack_size): 2) Backtrace logged from inside the template (each 6-frame block repeats until the process dies): 3) Template include counter: 4) Every nested include logs the same warnings because core passes only HOW TO REPRODUCE<\/p>\n\n\n\n On my install the core callback is still present on both hooks when the checkout renders.<\/p>\n\n\n\n WORKAROUND I AM USING <\/p>\n","protected":false},"template":"","class_list":["post-19026187","topic","type-topic","status-publish","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/topic\/19026187","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/topic"}],"about":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/topic\/19026187\/revisions"}],"wp:attachment":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/media?parent=19026187"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Since updating to WooCommerce 11, the checkout page shows an endless spinner. The AJAX request ?wc-ajax=update_order_review<\/code> never finishes: the PHP process is killed and LiteSpeed returns HTTP 503. get_refreshed_fragments<\/code> and every other wc-ajax endpoint work normally (~0.3s).<\/p>\n\n\n\n
Your templates fc\/checkout-steps\/checkout\/form-billing.php<\/code> and form-shipping.php<\/code> fire the core actions for compatibility:<\/p>\n\n\n\ndo_action( 'woocommerce_checkout_billing', $checkout ); \/\/ form-billing.php\ndo_action( 'woocommerce_checkout_shipping', $checkout ); \/\/ form-shipping.php, line 78<\/code><\/pre>\n\n\n\nWC_Checkout::checkout_form_billing<\/code> \/ checkout_form_shipping<\/code> hooked on those actions. Fluid Checkout is supposed to remove them, but with WooCommerce 11 the remove_action()<\/code> no longer matches the registered callback, so the core method stays attached. The template fires the action \u2192 core method calls wc_get_template('checkout\/form-billing.php')<\/code> \u2192 Fluid Checkout’s template override is loaded again \u2192 it fires the action again \u2192 infinite loop until the process is killed.<\/p>\n\n\n\narray( $this, 'method' )<\/code>), which is why the old remove_action( $hook, array( WC()->checkout(), 'checkout_form_billing' ) )<\/code> silently fails.<\/p>\n\n\n\n
PHP Fatal error: Maximum call stack size of 8339456 bytes reached during compilation \u2026\/fluid-checkout\/templates\/fc\/checkout-steps\/checkout\/form-shipping.php on line 64<\/p>\n\n\n\n
04 wc_get_template
05 WC_Checkout->checkout_form_billing
06 WP_Hook->apply_filters
07 WP_Hook->do_action
08 do_action
09 include
10 wc_get_template
11 WC_Checkout->checkout_form_billing
12 WP_Hook->apply_filters
\u2026
Identical pattern for checkout_form_shipping<\/code> \/ form-shipping.php.<\/p>\n\n\n\ncheckout\/form-billing.php<\/code> included 38,050 times in a single update_order_review request before the process was killed.<\/p>\n\n\n\n$checkout<\/code>, not your variables:
PHP Warning: Undefined variable $is_billing_same_as_shipping in \u2026\/form-billing.php on line 23
PHP Warning: Undefined variable $billing_same_as_shipping_fields in \u2026\/form-billing.php on line 37
PHP Warning: foreach() argument must be of type array|object, null given in \u2026\/form-billing.php on line 37
PHP Warning: Undefined variable $billing_only_fields in \u2026\/form-billing.php on line 49<\/p>\n\n\n\n\n
?wc-ajax=update_order_review<\/code>: it never returns (503 on LiteSpeed, 500\/timeout elsewhere). On PHP 8.3 the “Maximum call stack size” fatal above appears in debug.log.<\/li>\n\n\n\n
https:\/\/pastebin.com\/RcfdiRE7<\/a><\/li>\n\n\n\n
https:\/\/pastebin.com\/6nH7vtZP<\/a>
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A mu-plugin that blocks re-entry of the two templates via the wc_get_template<\/code> filter (returns an empty file when the same template is requested while already rendering). With this in place update_order_review completes in ~0.6s and the checkout works. It is a band-aid; the proper fix is to make the core callback removal work with WooCommerce 11 (match by method name across array callbacks and Closures, or remove the do_action<\/code> from the templates and re-add only third-party callbacks).<\/p>\n\n\n\n