Hey @zorak2, that error means the server accepted and closed the connection without sending a response. This will happen in most common cases due to one of the following:
- You have entered an invalid port - be sure you are using port 4747 to connect with SFTP
- You are using a non sudo user in an attempt to connect to SFTP
- Only sudo and better privileged users are permitted to access SFTP, all other users must use FTP/S. The limited shell environment that we use with QuickBox handles it this way to ensure no users break out of their assigned directories.
Double check to make sure these conditions are met and that you are not falling into one of those items. This error will only occur from such variables.