Securty Header not Valid Error

[tmscrap]

I am trying to activate a WebPayment Pro account on a Magento site - getthing the following message when I try to process payment direct.

PayPal gateway has rejected request. Security header is not valid (#10002: Security error).

Have re-entered all the security data again but getting the same error message ... PayPal help desk says the Account is setup correctly and ready to go.

Thanks, if you can help -

Allan

[ray_at_fyhealth]

I was also getting this problem and was told by Paypal that this is because my Checkout Express was set to SANDBOX MODE instead of LIVE MODE. I changed it to LIVE in my cart's admin settings and the error did not appear again.

Hope this helps.

Ray.