426 Connection closed; transfer aborted

[snpnlm]

(1972664) 2018/6/14 22:44:50 - (not logged in) (10.202.187.129)> Connected, sending welcome message...
(1972664) 2018/6/14 22:44:50 - (not logged in) (10.202.187.129)> USER faxftp
(1972664) 2018/6/14 22:44:50 - (not logged in) (10.202.187.129)> 331 Password required for faxftp
(1972664) 2018/6/14 22:44:50 - (not logged in) (10.202.187.129)> PASS ************
(1972664) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> 230 Logged on
(1972664) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> PORT 10,202,187,129,207,19
(1972664) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> 200 Port command successful
(1972664) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> LIST
(1972663) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> 150 Opening data channel for directory list.
(1972663) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> disconnected.
(1972663) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> 426 Connection closed; transfer aborted.
(1972663) 2018/6/14 22:44:50 - faxftp (10.202.187.129)> could not send reply, disconnected.
(1972664) 2018/6/14 22:44:51 - faxftp (10.202.187.129)> 150 Opening data channel for directory list.
(1972664) 2018/6/14 22:44:51 - faxftp (10.202.187.129)> 426 Connection closed; transfer aborted.
(1972664) 2018/6/14 22:44:51 - faxftp (10.202.187.129)> disconnected.

[botg]

Which FTP client software (product and version) are you using?

[snpnlm]

Application access FileZilla Server, application suddenly appears Unknown Error. Grab the 426 error at FileZilla Server. Reboot the application and restore normal

[boco]

Please answer botg's question first. Application accessing the FTP server = FTP client.