If you receive a message like this when attempting to authenticate your product, it is possible that the internet connection between your device and DLsite is failing / being interrupted by something.
Please note that some security software may interfere with the functionality of protection and authentication software.
If you are unable to authenticate, please check [ How to Change Your Security Settings ] . You may wish to try turning off temporarily the firewall settings of Windows and other security-related software when downloading, extracting and executing the file, or setting an exception rule for the product folder/file.
Also, please note that you must be able to access dlsite.com via port 443 in order to authenticate products successfully.