The most common reason for an error to occur is due to your credit card being declined. This usually occurs because your credit card company is worried about credit card fraud and prevents you from doing multiple online transactions.
To resolve this, call your credit card company and make sure they know this was a valid charge. You can then hit the back button and try again. Our system prevents duplicate orders, so it won't be possible to double order.
This error only relates to your attempt to add on a new item to your order. Any previous items where successfully processed and you will be receiving confirmation by email.
We are being notified of this error by an automated system, but please contact us at firstname.lastname@example.org so we can fix any errors that may have occurred. So sorry for the inconvenience and thank you for your patience.