Hi miabprja,

Please post your message over here only so that we will have a complete thread for this issue.

You have to check first from your affiliate account whether you are able to browse or search for a product. If you are able to do it then there might be a case of misconfiguration in api (Please check if you have included AmazonProductAPI class and calling it properly).

For checking configuration, follow the steps in following link (This is step by step procedure to create account and confirm it):

http://www.wp-amazon-plugin.com/register-amazon-affiliate-product-advertising-api/

Hi miabprja,

Before using Amazon product API you have to become an affiliate first and then have to register for Product API developer account. They will give you your associated ID and Amazon secrete access keys. There might be 1 cases for getting this error:

1: you are not using correct authentication data provided by Amazon affiliate network. 2: You have not configured Amazon product api.

follow the instruction provided in the following link:

http://docs.aws.amazon.com/AWSECommerceService/latest/DG/prod-adv-api-dg.pdf

This is very easy and even you can check api from your account to check your authentication credetials.

What kind of product advertising API are you using? Give some brief description so that someone can help.