It never works and the returning code is always 0. I've been there and have the 'T' shirt 😆.
Get in contact with sales@magix.net with your original sales receipt from your original purchase and they will send you a new code. This is a limited amount of activations though so I'm not sure how many an individual is allowed. (I think it was about five when they told me I would have to repurchase it again but it could also be a time limit, I'm not sure).
Although your post is clearly related to the original question, please create a new thread with your question, including details of your computer (see this post) and the exact version of MEP Premium which you have reinstalled.