10002 Security error - Security header is not valid

[helpme]

I am in the final stages of transfering my 1.3.7 cart over to 1.3.8a and when I did a test purchase, I get the following error after confirming the order.

[scr]http://www.mommyandbabyessentials.com/test/includes/templates/template_default/images/icons/error.gif[/scr] 10002 Security error - Security header is not valid

I can not find anything about this error.

I am using website payment pro, express checkout check/money order and local pick up.

Any ideas what the problem is?
Thanks!!

mommyandbabyessentials.com/test

[DrByte]

That means you've not entered your PayPal credentials properly in the admin.

[helpme]

I went back through and reentered everything and I am still getting the error. Just to be sure, I need to enter my paypal info into the express checkout correct?
This is what I have for my WPP

Enable this Payment Module
True

Sort order of display.
1

Payment Zone
--none--

Set Order Status
Pending [1]

Set Unpaid Order Status
Pending [1]

Payment Action
Final Sale

Transaction Currency
Selected Currency

PayPal Mode
PayPal

Live or Sandbox
live

Debug Mode
Log File

Paypal Express Checkout

Enable this Payment Module
True

Sort order of display.
2

Payment Zone
--none--

Set Order Status
Pending [1]

Set Unpaid Order Status
Pending [1]

Set Refund Order Status
Pending [1]

Express Checkout: Require Confirmed Address
No

Express Checkout: Select Cheapest Shipping Automatically
Yes

Express Checkout: Skip Payment Page
Yes

Express Checkout: Automatic Account Creation
Yes

Payment Action
Final Sale

Transaction Currency
Selected Currency

PayPal Page Style
Primary

API Signature -- Username
api signature from paypal

API Signature -- Password
password is here from paypal

API Signature -- Signature Code
my signature from paypal is here

PayPal Mode
PayPal

any idea what I am missing?
Thanks!! I think this is my final step before going live!!

[BarryLegal]

Any answer on this? I'm getting the same error, using Paypal Website Payment Pro

[DrByte]

The answer is the same. You've supplied incorrect credentials in one or more of your PayPal modules.

[Bujinkan]

The answer is the same. You've supplied incorrect credentials in one or more of your PayPal modules.

No, this is not the correct answer. All credentials have been thoroughly verified and I still get the same error. It has to do with a security patch update that is not working correctly but I cannot identify it. This comes from both PayPal and my hosting server. There is a problem with the Zen Cart security patch update. Does anyone other than the guy who keeps repeating the same answer actually have the right answer? Thanks.