Hi there,
I went through a mock checkout and I was able to replicate the error at the top of the page on the checkout screen. It was before entering any shipping information or payment so it does not appear to be related to the checkout gateway. Here is a screenshot of the errors that I found: https://d.pr/free/i/D5jmIV.
This usually means there is a theme conflict or plugin issue. You can read more about plugin and theme conflicts here: ?https://docs.woocommerce.com/document/woocommerce-self-service-guide/
The best way to determine if the issue is being caused by a theme and/or plugin is to do the following:
1. Temporarily switch your theme back to the Storefront or Twenty Seventeen Theme.
2. Disable all plugins except for WooCommerce and Paypal.
3. Test to see if the issue has been resolved.
If that resolves the issue, then one-by-one you can switch back your theme and re-enable your plugins, testing in between, until you find the one causing the conflict.
Health Check is a tool that can be useful for debugging, though it requires an official default theme like Twenty Seventeen. On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you while you’re logged in to that session without affecting normal visitors to your site.
Hope this helps! If you have any other questions, do not hesitate to let us know!
