When processing orders you might come across the "Invalid SOAP message due to XML Schema validation failure. (...): CountryOfOrigin element is invalid - The value (value) is invalid according to its datatype" error.
This error is shown when the value entered for the Country Code for a SKU (within the Packaging) is invalid.
Feel free to follow the step-by-step guide written below or the video guide, as you prefer:
To do so:
1. Find the order through any of the possible ways (after Import Orders, Batches, Order History, etc) as it applies to the case
2. Click the edit button of the order you wish to change
3. Select the Packaging tab
4. Make the necessary changes in the order, entering a valid country code
5. Press Save to apply the changes
If the rest of the order's information is correct, you will be able to process it.