(400) Bad Request for execute payment (express checkout with REST API)

[CoderA]

Account: Sandbox

The create payment (API: https://api.sandbox.paypal.com/v1/payments/payment) is creating the payment and returning the success status.

The Authorize function returns a payer id which is passed to execute API (API: https://api.sandbox.paypal.com/v1/payments/payment/<paymentId>/execute/), which returns a bad request.

I have verified the correctness of the Authorization token, payment Id and the payer id, and they are as expected.

Kindly help. Kindly let me know if I need to furnish more details.

[LRodrigues]

I have the same problem.

The payment is created successfully, but I can't execute it.

[LRodrigues]

Well... I was using a model I copied from somewhere in the documentation, then I realized there was a invoice_number parameter. This parameter must be unique and it is not validated by the time you create the payment, but when you execute the payment.
Hope this helps.