Are you getting following error

SetExpressCheckout API call failed. Detailed Error Message: Security header is not validShort Error Message: Security errorError Code: 10002Error Severity Code: Error

First thing to check if you might be using SandBox API credentials for LIVE payment of PayPal Live API credentials for sandbox.

Else you might have one of the following issue

One of the following error messages also may accompany code 10002:

  • 10002: Account locked – The user account is locked
  • 10002: Authentication/Authorization Failed – Account is locked or inactive
  • 10002: Internal Error – Account is locked or inactive
  • 10002: Internal Error – Internal Error
  • 10002: Authentication/Authorization Failed – Account is not verified
  • 10002: Authentication/Authorization Failed – API access is disabled for this account
  • 10002: Authentication/Authorization Failed – Client certificate is disabled
  • 10002: Authentication/Authorization Failed – Internal Error
  • 10002: Authentication/Authorization Failed – This call is not defined in the database!
  • 10002: Authentication/Authorization Failed – Token is not valid
  • 10002: Receiving Limit exceeded – You’ve exceeded the receiving limit. This transaction can’t be completed
  • 10002: Restricted account – Account is restricted