Learning to build an e-commerce website based on WP e-commerce <snip/>, payment is supported by PayPal.
When I tried to use Paypal Express , it showed
"SetExpressCheckout API call failed.
Detailed Error Message: Security header is not valid
Short Error Message: Security error
Error Code: 10002
Error Severity Code: Error"
When I tried to sue PayPal Pro, it showed: "Security header is not valid"
My Paypal sandbox setting:
1. A seller account
2. A buyer account
3. A PayPal Payments Pro account
4. A buyer In-Store account (for Payment Card Credentials)
If I still couldn't work out in Sandbox mode, I get to open a real one for test.
Thanks for reading.