Overview
Your DNS cache stores the locations (IP addresses) of web servers that contain web pages that you have recently viewed. If the location of the webserver changes before the entry in your DNS cache updates, you can no longer access the site.
If you encounter a large number of HTML 404 error codes, you may need to clear your DNS cache. After you clear your DNS cache, your computer will query nameservers for the new DNS information.
For more information, please check How to Clear Your DNS Cache | cPanel & WHM Documentation