I've set up "Paypal Express Checkout" with all the credential and using the API signature as authentication method.
When I try to pay, it returns the message: "PayPal gateway has rejected request. Security header is not valid (#10002: Security error)"
I'm still in "developer mode", and I'm sure that these are the correct credential.
I also tried to turn off the "Enable SSL Verification", but the problem still persists.
Did anyone had this problem? And what is the solution?
Solved! Go to Solution.
enable log for a paypal method and then after check PayPal log and share Paypal log info into the issue.
Ok, I will do it!
Thank you so much Sunil!