Error when placing an order

Hi @esobol!

That error indicates that it’s outputting additional debug information before the AJAX data and is usually the result of a conflict, either from your theme or another plugin.

Official debug steps for this error can be found here: https://mikejolley.com/2015/11/12/debugging-unexpected-token-in-woocommerce-2-4/

I would recommend you temporarily switch to a default WordPress theme, like Storefont, and disable all your plugins except for WooCommerce core, to see if that resolves the issue.

If you don’t want to make this switch on your live production site, then I would recommend you use a free plugin like https://wordpress.org/plugins/wp-staging/ where you can do the test without it impacting your production site.

You can learn more about conflict testing here:

https://docs.woocommerce.com/document/how-to-test-for-conflicts/

Cheers!