When you are talking to a distributed FTPS server, it needs a PRET command to be issued before all calls to PASV. PASV doesn't work with standard FTP and distributed transfers. The client sends a PRET (PRE Transfer) command before PASV to inform the server what kind of command/transfer will be used.

In Auto FTP Manager, you can connect to the server using active mode. If you are connecting to the FTP server using the Active mode, you must set your firewall to accept connections to the port that the FTP client will open. Most Firewalls block those incoming connections so you need to configure your firewall to allow active mode connections.