This is because Google Chrome cannot connect to the port on the web server, hosting the website. Most likely because there is a problem with the web server or a firewall in between you and the web server. To troubleshoot this, see if you can connect to the website while logged onto the web server. If you can’t, it’s a problem with the configuration of the web server (most likely). Next try connecting from other machines to narrow down whether it’s the router not forwarding the traffic, blocking via the firewall, or a local firewall blocking the traffic.