To fix a DNS server error in your website, follow these steps:
1) Check the DNS server: Ensure that the DNS server is up and running. You can check it by using the "nslookup" command.
2) Check the DNS configuration: Check if the DNS configuration for your domain is correct. Make sure that the nameservers are set up correctly.
3) Clear the local DNS cache: Clearing the local DNS cache can help resolve the issue. This can be done by using the "ipconfig /flushdns" command in Windows or the "sudo killall -HUP mDNSResponder" command on a Mac.
4) Check for firewall blocks: Ensure that your firewall is not blocking incoming or outgoing DNS requests.
5) Restart the router: Restarting your router can also help resolve the issue.
6) Contact your hosting provider: If the issue persists, contact your hosting provider for further assistance. They can check the server logs and network configurations to identify the cause of the error.
7) Try a different DNS service: You can also try changing your DNS service to see if that resolves the issue.
Note: If the issue is not resolved by following these steps, it may be a problem with your website's code or server configuration.