The Last Upsell app offers upsells in a pop-up that displays only on the checkout order status page after the customer completes the order, making the app work as seamlessly as possible.

However, you might encounter this error if you have auto-fulfillment set up in your Shopify admin:

Something went wrong, we couldn't add the item to the order. Maybe the order has been fulfilled already? Please contact us for more details.

There can be two reasons for this error to occur:

Our app can no longer edit and add items to the order if it has already been fulfilled.

When the error appears, please check the order status of this particular order by going to Shopify admin > Orders and checking the status in the Fulfillment column. If the order is already fulfilled, it means it can't be edited, and no items (upsells) can't be added.

To disable automatic fulfillment in your store, you can:

Unfortunately, Shopify doesn't allow editing orders that have local delivery as a shipping method.

You can learn more about this in the Shopify Help Center.

UPDATE: We're planning to implement the measure to prevent the upsell pop-up from showing up when the order cannot be edited in the upcoming weeks.

For any questions you may have, please contact us using the chat icon at the bottom right corner of this page or at [email protected].