Use more useful language to explain that a shipping service is required

The default message is:

No valid shipping rates found for your order, and we require shipping service selection to complete checkout.
Please verify you have supplied all required information or contact us to resolve the issue.

This is not ideal UX, in my opinion. I feel like it explains it from the site owner's perspective, and not the customer's—that is, the customer has no idea what "valid shipping rates" means (since that really is referring to the Rules configurations for shipping methods, which customers shouldn't have to know anything about), and the lack of shipping rates is also possibly due to an invalid address (e.g., invalid combination of zip and state, or something). I propose the following:

No shipping services are available for your order.
Please verify that you have supplied a valid address or <a href="@url">contact us</a> to resolve the issue.

(@url would be mailto: the site's address.) Patch forthcoming.