This error usually occurs if you're using Google Chrome or a Chrome-based web browser, indicating an issue with the connection from your device to the website:
If you encounter it, you can try the following solutions:
First and easiest - check that your device is connected, otherwise restart your modem/router
Reset your network settings:
If you got Windows, check this article: How to reset network settings in Windows 10?
For Mac: Go to System Preferences → Network, select Wi-Fi, and click on the minus button to delete the current configuration. Then, click on the plus button and select Wi-Fi from the drop-down menu to set up a new connection
For Linux - open Terminal and use this command: sudo service network-manager restart
If you’re using a VPN, try disabling it
Disable your browser’s extensions - You can check how to do it for Google Chrome here: manage extensions
Update or reinstall your browser
If the issue persists, you can still verify that your website is working by using a different device as well as a different network; for example, on your mobile using data instead of Wi-Fi or using a proxy website, such as kproxy.com or proxysite.site.