New verison 4.2.5not working

Hi,

I investigated this issue and, at least in this case, it is not caused by Stripe.

I can reproduce the same infinite loading problem with Stripe disabled and Mercado Pago enabled. The browser console shows:

Uncaught TypeError: Cannot read properties of undefined
(reading '__maybeHideDefaultButtonOnInit')

The error happens inside Fluid Checkout 4.2.5:

wc.customPlaceOrderButton.__maybeHideDefaultButtonOnInit(
    $selectedMethod.val()
);

Fluid Checkout 4.2.5 replaces WooCommerce’s wc-checkout script. However, when it registers its replacement script, it does not include:

wc-custom-place-order-button

as a dependency.

WooCommerce’s original wc-checkout script includes this dependency. Because Fluid Checkout removes it, window.wc exists but wc.customPlaceOrderButton is undefined.

This causes the JavaScript execution to stop inside init_payment_methods(), before the selected payment method click event is triggered. As a result, payment gateways such as Mercado Pago do not finish initializing and the loading spinner remains visible indefinitely.

Therefore, this is not specifically a Stripe issue. Stripe may also trigger or expose the problem, but the root cause is the missing script dependency in Fluid Checkout 4.2.5.

The permanent fix in Fluid Checkout should be to add wc-custom-place-order-button to the dependencies of the replacement wc-checkout script:

wp_register_script(
    'wc-checkout',
    $this->get_script_url( 'js/checkout' ),
    array(
        'jquery',
        'woocommerce',
        'wc-country-select',
        'wc-address-i18n',
        'wc-custom-place-order-button',
        'fc-utils',
    ),
    null,
    array(
        'in_footer' => true,
        'strategy'  => 'defer',
    )
);

It would also be safer to check that the object exists before calling it:

if (
    window.wc &&
    wc.customPlaceOrderButton &&
    $selectedMethod.length
) {
    wc.customPlaceOrderButton.__maybeHideDefaultButtonOnInit(
        $selectedMethod.val()
    );
}

As a temporary workaround, site owners can add the following code to the child theme’s functions.php:

/**
 * Temporary fix for the missing Fluid Checkout 4.2.5 dependency.
 */
add_action( 'wp_enqueue_scripts', function () {
    if (
        is_admin()
        || ! function_exists( 'is_checkout' )
        || ! is_checkout()
    ) {
        return;
    }

    $scripts = wp_scripts();

    if (
        ! isset( $scripts->registered['wc-checkout'] )
        || ! wp_script_is(
            'wc-custom-place-order-button',
            'registered'
        )
    ) {
        return;
    }

    $checkout_script = $scripts->registered['wc-checkout'];

    if (
        ! in_array(
            'wc-custom-place-order-button',
            $checkout_script->deps,
            true
        )
    ) {
        $checkout_script->deps[] =
            'wc-custom-place-order-button';
    }

    wp_enqueue_script( 'wc-custom-place-order-button' );
}, 99 );

After adding the workaround, all page cache, optimization cache and CDN cache should be cleared.

If the original reporter has the same console error, it is very likely the same issue.