Currently, when a checkout fails due to a backend validation error (such as a referral code invalidation because the referrer has no address), the system defaults to a generic "There was a problem creating your order" message. There are no settings to enable more detailed or specific error messages for the customer.

The checkout error messages needs to be specific and descriptive regarding the cause of the failure. Specifically, if an order cannot be processed due to a Referral Code issue (e.g., the referrer is missing an address or the code is invalid), the error message should explicitly say: "Checkout failed due to invalid referral code" or "Unable to apply referral code." This informs the customer that the coupon is the problem, not the payment method or the website itself.

Why/how would it improve sales or efficiency?

Reduces Cart Abandonment: When customers see a generic "Problem creating order" error, they assume the website or payment gateway is broken and abandon the cart. If they are told the referral code is the issue, they can simply remove the code and proceed with the purchase.