结帐时出错 - Wordpress

Question

I have this extremely strange error that only happens when people try to order. Guests come onto our site and add stuff to their cart. Then they proceed to go to the checkout. On checkout when they click proceed to paypal they get the following error: "We were unable to process your order, please try again.". However on reloading the page the error is gone when they try to recheckout. No plugins or themes are conflicting as I checked all of them.

I did some debugging and I noticed that the reason the error is thrown is because of the function: wp_verify_nonce() I did some further debugging and found out that during the first time the user tries to checkout the above function is called. And returns false because the nonce is different when compared to what is currently hashed. However on the second checkout the above function returns true because the nonce is correct. This means that for some reason my nonce is wrong the first time. Does anyone know why?

I'm getting this problem on the following function: process_checkout() When the following command is run:

if ( empty( $_POST['_wpnonce'] ) || ! wp_verify_nonce( $_POST['_wpnonce'], 'woocommerce-process_checkout' )) {
    WC()->session->set( 'refresh_totals', true );
    throw new Exception( __( 'We were unable to process your order, please try again.', 'woocommerce' ) );
}

I tried my best to explain my issue but does anyone know why my nonce is wrong during checkout on the first time?

Answer 1

The issue isn't really with wp_verify_nonce() or the code you posted.

The way wp_nonce work is like a queue number, just like your processing number at the DMV.

My best guess on what's happening is an extra wp_nonce being created when people checkout and wp_verify_nonce() is receiving a different one from what's expected. There's no way for me to really identify where it's happening without looking at the code base.

If no custom code has been done for these parts then it really means there's a subtle plugin conflict with WooCommerce. It could be even a conflict with the theme.