This error (API returned an error: Invalid Currency) from Evri typically occurs when the courier does not support the selected currency. To resolve this issue please review the steps below:
For standard orders
Click Order then Overview.
Search for the relevant order.
Click Actions then Details.
Scroll down to find Currency.
Change the currency to Pound.
For Amazon orders
Click Order then Overview.
Tick the order.
Select Cancel and Delete from thew Bulk Actions dropdown.
Make the currency change in Amazon.
Allow the order to re-import into Mintsoft.
By following these steps, you should be able to resolve the error. If you have any issues, please speak with the Mintsoft support team or raise a support ticket.