My site is still under development so I’m running PayPal Express Checkout in Sandbox mode. It seems the problem, in my case, was being caused by an invalid token related to the Sandbox account I was using.
There is a problem with your PayPal Express Checkout configuration.
DoExpressCheckoutPayment API call failed.
Error Code: 10410
Error Severity Code: Error
Short Error Message: Invalid token
Detailed Error Message: Invalid token.
I have used a different Sandbox account and everything is working fine.
I’m also getting duplicate orders when using PayPal Express using the PayPal for WooCommerce plugin.
An order with the status ‘processing’ is created first which shows the correct products for the order and balance for the order.
Then another is created with the status ‘pending’ which has no products on it and a balance of 0.00.