1. server problem: the server of the HEYCode programming robot is out of order or maintenance, which leads to the failure of normal connection. In this case, you need to wait for the server problem to be solved before trying to connect.
2. Network problem: There is a problem with the network connection, because the Internet service provider (ISP) is out of order or the network settings are wrong. You can try to restart the router or connect to another network to see if it is your network problem.
3. Firewall or proxy settings: Some firewall or proxy settings will prevent access to HEYCode programming robots. You can try to turn off the firewall or proxy, and then try to connect again.