Why did I get API error code 10609?

Issue
PayPal returned API error code 10609 - Invalid transactionID (Transaction id is invalid) when calling the “DoAuthorization.”

Cause
The transaction ID is invalid. This message can be displayed with the DoAuthorization, DoCapture, DoReauthorization and DoVoid API calls.

Solution
Review the transaction ID and retry the request. Also, consult Express Checkout API Operations for more information on these API calls.