When shipping through Stallion, you might come across the error "STALLIONEXPRESS - failed to generate label: Country of origin is required for items when shipping to the US.".
This error is shown when you intend to ship and international shipment, but you're missing sending the SKU line details to comply with Customs requirements.
To solve the issue, you will have to:
1. Access Clients under the Maintenance dropdown
2. Select the Client that applies to the case
3. Press the Edit Button of the account related to the issue
4. Select the Carrier Options tab
5. Check the Always Send Custom Lines checkbox
6. Press Save to apply the changes; reprocess the order