The authenticity of host '55200805a (192.168.0.169)' can't be established.

This message usually appears when you are trying to connect to a remote server via SSH for the first time, and your local machine does not recognize the remote server's host key. The host key is used to authenticate the remote server and ensure that you are connecting to the correct server.

To proceed with the connection, you can verify the host key fingerprint with the server administrator or check the server's documentation for the correct fingerprint. Once you have verified the fingerprint, you can add it to your local machine's known_hosts file by typing 'yes' when prompted. After that, your local machine should recognize the remote server's host key and allow you to connect without displaying the warning message again.