Here are ways to resolve this issue:
- If you use a third-party integration such as a shopping cart, there may be a switch between Test/Sandbox and Live/Production processing. Check that the correct value is set.
- Supply an API URL if asked to do so. See NVP/SOAP API endpoints for a list of URLs.
- Copy and paste your API information into the cart again, ensuring there is no special formatting applied and no leading or trailing spaces or carriage returns.
- Verify the type of API information that the cart requires. Ensure in PayPal that you haven't requested the wrong information.
For ASP.NET
If you requested a second certificate:
- Delete the old certificate from the Windows Keystore.
- Install the new certificate.
- In addition, check that the permissions to the certificate are correct.
- Check that you're granting the correct user rights to the certificate (using the winhttpcertcfg command).
- For troubleshooting, try granting permissions to "Everyone" to see if this resolves the error. If it does, you know that you have a permissions issue.
See the Developer Portal for a complete list of NVP/SOAP API error codes.