I have configured Sandbox testing of PayPal direct payment method but getting the error while processing the order
Payment error: LongMessage: Security header is not valid ShortMessage: Security error ErrorCode: 10002
Some sites states that it is due to wrong credentials.
I have double checked the API Account Name, Password and Signature all seems to be correct. Here are some steps i followed while getting the API credentials from PayPal correct me if i am wrong.
1) Login to site https://developer.paypal.com
2) Enter Sandbox Site (https://www.sandbox.paypal.com/)
3) Go to Tools --> API Access
4) Request API Signature
5) After that i have also Enable Express Checkout to accept payments from online store.
I have only one confusion, I can see another API credentials under Business account which resides on https://developer.paypal.com which is accessible from "Profile" option. which has different API credential than that on Sandbox site (https://www.sandbox.paypal.com/).I have tried it too but never works and give merchant account configuration error.