Error -57 when using Netscape Navigator to ftp

If you get an "error -57" when you try to ftp files through Netscape
Navigator, then this means the ftp server is too busy at the moment; try
again later to access it.
This error message results when the ftp server opens a socket, but then
decides it is too busy, and immediately drops the connection.  This is a
server problem and doesn't indicate anything wrong with Netscape Navigator.