SetExpressCheckout Error

I recently updated to woocommerce 2.3.11, could it be a woocommerce issue?

Hello gremelle,

I just seen your email, I will check it and get back to you soon.

Thanks.

I have check this plugin on woocommerce 2.3.11 version, for me it’s working fine.

Why do I receive a “Security header is not valid” error?

On occasion when setting up PayPal Digital Goods and attempting to checkout for the first time, store managers encounter the following error:

Calling PayPal with action SetExpressCheckout has Failed: Security header is not valid
This indicates your API credentials are not valid for the transaction. Invalid API credentials can be caused by a few things:

Using sandbox API credentials for live transactions (or vice versa);
Using API credentials for an account that has not been correctly set up to use PayPal Digital Goods;
Incorrectly copy and pasted your API credentials – the API signature in particular can on occasion include a period character (.) which means when double clicking the signature to select it, only part of the signature will be selected.

Please also refer this https://developer.paypal.com/docs/classic/api/apiCredentials/#navigate-to-the-api-access-page

Please mail me directly if any problem [email protected]

Thanks @johnwickjigo

I will check with paypal, it seems my issue is with the API Credentials

Thank you gremelle ??