kex_exchange_identification: Connection closed by remote host

This error message means that the connection to the remote host using the Key Exchange (KEX) protocol could not be established or has been closed. There could be various reasons for this, such as network connectivity issues, incorrect server settings, or firewall restrictions. It is recommended to check the network connection and server settings and try again. If the issue persists, contacting the system administrator or technical support may be necessary for further troubleshooting.