Title: Security header error – Security header is not valid
Last modified: December 10, 2021

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# Security header error – Security header is not valid

 *  Resolved [tcognition](https://wordpress.org/support/users/tcognition/)
 * (@tcognition)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/)
 * Though I have entered correct credentials, when I go for checkout log in to paypal
   account and select my credit card option it redirects to website checkout page
   and gives following error
 * **An error occurred. We were unable to process your order, please try again.**
 * And the log shows following error what to do with this?
 *  [TIMESTAMP] => 2021-11-11T13:45:31Z
    [CORRELATIONID] => f9b0ecd1e9736 [ACK] 
   => Failure [BUILD] => 56144363 [L_ERRORCODE0] => 10002 [L_SHORTMESSAGE0] => Security
   error [L_LONGMESSAGE0] => Security header is not valid [L_SEVERITYCODE0] => Error
 * Please help me to resolve it.
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fsecurity-header-error-security-header-is-not-valid%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 5 replies - 1 through 5 (of 5 total)

 *  Plugin Author [WebToffee](https://wordpress.org/support/users/webtoffee/)
 * (@webtoffee)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/#post-15153481)
 * Hi [@tcognition](https://wordpress.org/support/users/tcognition/),
 * The error you have mentioned is related to your API keys and not the plugin. 
   Please check the following.
 * 1) Make sure you are using only the NVP/SOAP API keys from PayPal. (NOT the REST
   API)
 * 2) Make sure that the keys you’ve entered match the “Environment” under the plugin
   setting. If “Environment” is set to “Sandbox Mode”, you must enter the Sandbox
   keys. If “Environment” is set to “Live Mode”, it must be the Live keys. (Your
   Live and Sandbox keys will be different.)
 * 3. Make sure the email address verification is completed for the PayPal business
   account.
 *  Thread Starter [tcognition](https://wordpress.org/support/users/tcognition/)
 * (@tcognition)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/#post-15155021)
 * Hi, thanks for your reply. I haven’t got verification email on registered email
   id. Aslo the API keys are not from rest api and environment is also set to live
   mode.
 *  Plugin Author [WebToffee](https://wordpress.org/support/users/webtoffee/)
 * (@webtoffee)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/#post-15157306)
 * Hi [@tcognition](https://wordpress.org/support/users/tcognition/),
 * Kindly makes sure that the email verification is completed first in order to 
   start receiving payments.
 *  Thread Starter [tcognition](https://wordpress.org/support/users/tcognition/)
 * (@tcognition)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/#post-15159401)
 * Hi,
    I understand your concern. But I am not getting verification email.
 *  Plugin Author [WebToffee](https://wordpress.org/support/users/webtoffee/)
 * (@webtoffee)
 * [4 years, 5 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/#post-15179134)
 * Hi [@tcognition](https://wordpress.org/support/users/tcognition/),
 * As that is a PayPal side issue, kindly contact [PayPal Helpdesk](https://www.paypal.com/in/smarthelp/contact-us)
   for assistance.
 * The security header error will be resolved automatically once you verify your
   PayPal account email address.

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘Security header error – Security header is not valid’ is closed to new
replies.

 * ![](https://ps.w.org/express-checkout-paypal-payment-gateway-for-woocommerce/
   assets/icon-256x256.gif?rev=3385064)
 * [Payment Gateway of PayPal for WooCommerce](https://wordpress.org/plugins/express-checkout-paypal-payment-gateway-for-woocommerce/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/express-checkout-paypal-payment-gateway-for-woocommerce/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/express-checkout-paypal-payment-gateway-for-woocommerce/)
 * [Active Topics](https://wordpress.org/support/plugin/express-checkout-paypal-payment-gateway-for-woocommerce/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/express-checkout-paypal-payment-gateway-for-woocommerce/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/express-checkout-paypal-payment-gateway-for-woocommerce/reviews/)

 * 5 replies
 * 2 participants
 * Last reply from: [WebToffee](https://wordpress.org/support/users/webtoffee/)
 * Last activity: [4 years, 5 months ago](https://wordpress.org/support/topic/security-header-error-security-header-is-not-valid/#post-15179134)
 * Status: resolved