A "connection refused" error occurs when your connection to a server is refused. This can happen for a variety of reasons, including:

1. The server is not responding: If the server is not responding, it may be temporarily down or experiencing maintenance. In this case, the connection refused error may occur.
2. Your network is not connected: If your network is not connected to the server, you may not be able to connect to it. In this case, the connection refused error may occur.
3. There is a firewall or security software阻止了连接: Some firewalls and security software may block connections to servers. In this case, the connection refused error may occur.
4. There is a problem with the server's configuration: If the server's configuration is incorrect, it may not be able to accept connections. In this case, the connection refused error may occur.
5. The server is running an outdated version: If the server is running an outdated version of the software or programming language it is using, it may not be able to accept connections. In this case, the connection refused error may occur.

To resolve a connection refused error, you can try the following steps:

1. Check the server's status: Check the server's status to see if it is currently online and responding to connections.
2. Check your network: Check your network to see if it is connected to the server.
3. Check your firewall or security software: Check your firewall or security software to see if it is blocking connections to the server.
4. Check the server's configuration: Check the server's configuration to see if it is properly configured to accept connections.
5. Check for outdated software or programming language: Check for outdated software or programming language that may be preventing the server from accepting connections.