Overview of the Issue
When using WooCommerce PayPal Payments version 2.9.1, orders placed with currencies other than the default site currency fail with the error CANNOT_MIX_CURRENCIES:
Failed to process the payment. Please try again or contact the shop admin. [UNPROCESSABLE_ENTITY] The requested action could not be performed, semantically incorrect, or failed business validation. https://developer.paypal.com/docs/api/orders/v2/#error-CANNOT_MIX_CURRENCIES PayPalGateway.php:685 [UNPROCESSABLE_ENTITY] The requested action could not be performed, semantically incorrect, or failed business validation. https://developer.paypal.com/docs/api/orders/v2/#error-CANNOT_MIX_CURRENCIES OrderEndpoint.php:584 Order status changed from Pending payment to Failed.
Workaround
This issue is fixed. Updating to the latest version solves it on your site, so you only need this workaround if you can’t update yet.
The recommended workaround is to downgrade WooCommerce PayPal Payments to version 2.9.0. This version does not exhibit the issue, and payments will process correctly in different currencies.
WooCommerce team is already aware of the issue and they are working in a general solution as it affects several multicurrency plugins.
