421 Can't open data connection. (1)

Hello,
I just installed the latest version 1.1.984 and I noticed that I'm getting the following when I try to connect to an FTP server here in the company. Please advise. Thank you...

200 PORT command successful
Opening data connection IP: 47.103.83.153 PORT: 1939.
LIST -aL
421 Can't open data connection. (1)
NOOP
421 Can't open data connection. (1)
NOOP
421 Can't open data connection. (1)
NOOP
...

Here's the log:

SmartFTP v1.1.984.15
Resolving host name 47.230.2.10...
Connecting to (47.230.2.10) -> IP: 47.230.2.10 PORT: 21
Connected to (47.230.2.10) -> Time = 0ms
Socket connected waiting for login sequence.
220-PROXY FTP server
220-Authenticate at PROXY FTP server before onward connection
220-local_user@remote.host.com or local_user@localhost
220 local_user has to be registered on the PROXY server
USER 5005774@134.150.68.25
331 Password required for 5005774.
PASS (hidden)
230-User 5005774 authenticated
230 Login to server with "user" command.
SYST
500 'SYST': command not understood.
FEAT
500 'FEAT': command not understood.
TYPE I
200 Type set to I.
REST 0
502 REST command not implemented.
PWD
530 Please login with USER and PASS.
PASV
530 Please login with USER and PASS.
PORT 47,103,83,153,15,10
200 PORT command successful
Opening data connection IP: 47.103.83.153 PORT: 3850.
LIST -aL
421 Can't open data connection. (1)[/b]
NOOP
421 Can't open data connection. (1)

Hello ...

The problem is with the FTP proxy login. What FTP Proxy server are you connecting to? vendor of the software/hardware?

Thanks

Thanks for your reply. I just figured it out...
It was in the Favorite-->Connection--> Proxy settings. I didn't have the 'type' set to 'USER user@host' and the Proxy 'Host' was blank.
Thanks again.
Cheers