Nobody will provide diagnostics instructions except the developer of the application you use. The registration info as well as other sensitive data related to your address, payment, credit card, etc., are handled by the one you've purchased the IEDL Management System in the first place. However, since the official website doesn't exist anymore, I recommend checking the installation directory. Browse to the application's directory, then look for the README files or URL files. First try accessing the official website, and if it's not working look through the README files for contact methods. You should find all the necessary data to contact him. No other information can be gathered through Google.
