No connection could be made because the target machine actively refused it.

How do I fix it?

If it's server issue, you can't do nothing, [[[SHOWLOG][/SHOWLOG]][/[SHOWLOG][/SHOWLOG]]][/[[SHOWLOG][/SHOWLOG]][/[SHOWLOG][/SHOWLOG]]]

i have the same problem. i am using guildftpd as the server and am trying to connect to myself... for now
i have checked my firewall status, used ad-aware and all that

[21:04:09] SmartFTP v2.0.993.6
[21:04:09] Resolving host name "xx.xxx.xxx.xxx"
[21:04:09] Connecting to xx.xxx.xxx.xxx Port: 21
[21:04:31] No connection could be made because the target machine actively refused it.
[21:04:31] Client closed the connection.
[21:04:31] Active Help: https://www.smartftp.com/support/kb/58
[21:04:31] Cannot login waiting to retry (30s)...
[21:05:01] Continue to login attempt 2...
[21:05:01] Resolving host name "xx.xxx.xxx.xxx"
[21:05:01] Connecting to xx.xxx.xxx.xxx Port: 21

It seems the server is set up incorrectly, no service is listening on port 21 on the target machine, or a firewall blocks incoming connections to port 21.