paypal express checkout =>Error: Security header is not valid

Question

Error : Security header is not valid Array

(
    [TIMESTAMP] => 2014%2d04%2d29T07%3a24%3a29Z
    [CORRELATIONID] => 6af6749c848d6
    [ACK] => Failure
    [VERSION] => 109%2e0
    [BUILD] => 10800277
    [L_ERRORCODE0] => 10002
    [L_SHORTMESSAGE0] => Security%20error
    [L_LONGMESSAGE0] => Security%20header%20is%20not%20valid
    [L_SEVERITYCODE0] => Error
)

I am getting this error again and again and cannot move ahead. I had checked all the api username, password and signature, all are correct, but the main problem is that, all the things are already stored in paypal sandbox account but it cannot give back to the page. I mean to say transection is shown in sandbox account but it cannot send forward to the display page. Am I wrong somewhere?

Answer 1

generally this error means you are not using the correct API credentials. If you are convinced your credentials are correct then take a look at your endpoint. Sandbox credentials will not be valid in the production environment and live credentials will produce this error in the sandbox

Answer 2

I had this issue because my login contained "+"(plus) sign. Finally I manually decoded it to "%2B" as described here http://www.zen-cart.com/showthread.php?80849-Plus-sign-%28-quot-quot-%29-in-user-name-causes-security-header-failure-in-Paypal-Express-Checkou and the issue gone.

Answer 3

It doesn't always mean invalid API credential or wrong endpoint

If you're absolutely sure in this info, check the encoding you're making your request with - it should be UTF-8 without Byte-Order Mark (BOM), e.g (in Visual C# .NET)

var requestEncoding = new UTF8Encoding(false); // UTF-8 without BOM

using (var streamWriter = new StreamWriter(request.GetRequestStream(), requestEncoding))
{
    streamWriter.Write(requestBody);
}

This is not a default value, and it helped me after an hour of checking everything

Of course, make sure all of your parameters are URL encoded, too

Answer 4

API_USERNAME API_PASSWORD API_SIGNATURE PAYPAL_URL

apart from them change this too:

** (from Sandbox > Live)**

Answer 5

Wrong credentials Make sure that you've put your API Username, API Password and API Signature correctly. Sometimes it happens that during copy and paste there is accidently a space added, this would trigger this error. Doublecheck this settings in the SDK or in the admin panel of your third party shopping cart.

Wrong Endpoint This error would come up if you send the data to the wrong endpoint. Make sure that you sending the live credentials and data to our live endpoint. When you want to test your store make sure that you use our test endpoint and the credentials from your sandbox test account. If you are using a third party shopping cart, make sure that your store is running in test or live mode, regarding which credentials you are using. FOR LIVE

https://api-3t.paypal.com/nvp?&user=xxxxxxxxxx&pwd=xxxxxxxxxx&signature=xxxxxxxxxx&version=70.0&METHOD=SetExpressCheckout&RETURNURL=http://www.paypal.com/test.php&CANCELURL=http://www.paypal.com/test.php&PAYMENTACTION=Sale&AMT=50&CURRENCYCODE=USD

FOR SANDBOX

https://api-3t.sandbox.paypal.com/nvp?&user=xxxxxxxxxx&pwd=xxxxxxxxxx&signature=xxxxxxxxxx&version=70.0&METHOD=SetExpressCheckout&RETURNURL=http://www.paypal.com/test.php&CANCELURL=http://www.paypal.com/test.php&PAYMENTACTION=Sale&AMT=50&CURRENCYCODE=USD

For reffrence link