Step 1: Log into Amazon Seller Central, click on Settings, then click on User Permissions
Step 2: Scroll to the section that says Third-Party Developers and Apps and clicks on "Visit Manages Your Apps
Here you will the developer nickname asinzen listed along with the asinzen developer ids. Note under status, and you should see Active. If not, you will have to activate it and update your MWS Authen Token.
1. Login into Amazon Seller Central
3. Locate the row with asinzen and look under the column Status. If the status is Active, then asinzen is an active developer on your account. If under status, you see Disabled will have to click enable, which will generate a new MWS Auth token that you will have copy add to your account on the asinzen web portal.