Sometimes when an order has failed in your Shiptheory, you may see the error listed as;
"Unable to load your XXXX carrier settings" - The "XXXX" in this example is a replacement for the carrier name, as this can effect all carriers.

Essentially, the reason for this, is because the order has tried to send to a carrier that Shiptheory no longer recognises as being on your account. The most common reason for this can be when you delete a carrier from your account, and then re-add it, your Shiptheory rules will still be pointing at the old "version" of that carrier on your account.

The solution here is to head into your rules, and edit the rules pointing at that carrier. You'll just need to re-select the needed carrier and service on those rules and hit save:

Once all your rules have been updated to point at the "new version" of your carrier, future orders should not have this issue. As for failed orders with this error, you can hit "retry" on them in the Shiptheory dashboard; they'll then re-run through your rules and this time match to the new version to book successfully:

If you have any issues from there, or are unsure, please feel free to Contact Support.