You will see this page because Gateway is not returning the IP address for the blocked domain. As a result, your browser cannot take you to that website.
However, this may be confusing for some people as they may think that their Internet is not working.
You can remove this confusion by show Cloudflare Gateway's block page to explain to the end user why a website is blocked.
Here's how you can configure a block page using Gateway's policy engine:
In the policy configuration page, enable the block by toggling the switch annotated above. Hit 'Save'.
To fix the browser erorr go to the Account page to download a certificate given by Cloudflare.
You will need to add the certificate to your system to ensure your web browser will use this certificate to establish HTTPS connections.
Now close the menu and if your system asks for admin permission enter your password or use your fingerprint ID to confirm the changes.
If you are not using Firefox, you can skip to the next section.
Follow the instructions below to finish configuring the block page:
Enter about:config in the address bar
Click on Accept the risk! if you see a prompt from Firefox.