Ametex - Digital Marketing and SEO WordPress Themes Purchase code registration problem

I have just bought Ametex - Digital Marketing and SEO WordPress Themes, uploaded but I have a problem with registration code. The message is

" This product is in use on another domain:

Page Not Found

The page you are looking for could not be found. Check the address bar to ensure your URL is spelled correctly. If all else fails, you can visit our home page at the link below.

Visit the Home Page
Are you using this theme for a new site? Please purchase a new license
"
How can I solve this problem?

Hi

contact theme Author and let them know How to Contact your purchased theme Author, theme author will be happy to assist you.

Thanks