Transfer channel can't be opened.

Using GUI, Commander with the latest version of WinSCP. This same type of error occurs from the machine and other machines in the environment running Filezilla.

Here is the Full Log:

. 2016-01-05 15:28:34.035 --------------------------------------------------------------------------
. 2016-01-05 15:28:34.035 WinSCP Version 5.7.6 (Build 5874) (OS 6.1.7601 Service Pack 1 - Windows 7 Professional)
. 2016-01-05 15:28:34.035 Configuration: HKCU\Software\Martin Prikryl\WinSCP 2\
. 2016-01-05 15:28:34.035 Log level: Normal
. 2016-01-05 15:28:34.035 Local account: MSB\chooks
. 2016-01-05 15:28:34.035 Working directory: C:\Program Files (x86)\WinSCP
. 2016-01-05 15:28:34.035 Process ID: 5900
. 2016-01-05 15:28:34.035 Command-line: "C:\Program Files (x86)\WinSCP\WinSCP.exe"
. 2016-01-05 15:28:34.035 Time zone: Current: GMT-5, Standard: GMT-5 (Eastern Standard Time), DST: GMT-4 (Eastern Daylight Time), DST Start: 3/13/2016, DST End: 11/6/2016
. 2016-01-05 15:28:34.035 Login time: Tuesday, January 05, 2016 3:28:34 PM
. 2016-01-05 15:28:34.035 --------------------------------------------------------------------------
. 2016-01-05 15:28:34.035 Session name: GAA (Site)
. 2016-01-05 15:28:34.035 Host name: sftp.general-assurance.com (Port: 21)
. 2016-01-05 15:28:34.035 User name: 7065GAA (Password: Yes, Key file: No)
. 2016-01-05 15:28:34.035 Transfer Protocol: FTP
. 2016-01-05 15:28:34.035 Ping type: C, Ping interval: 30 sec; Timeout: 15 sec
. 2016-01-05 15:28:34.035 Disable Nagle: No
. 2016-01-05 15:28:34.035 Proxy: none
. 2016-01-05 15:28:34.035 Send buffer: 262144
. 2016-01-05 15:28:34.035 UTF: 2
. 2016-01-05 15:28:34.035 FTP: FTPS: Explicit SSL; Passive: Yes [Force IP: A]; MLSD: A [List all: A]
. 2016-01-05 15:28:34.035 Session reuse: Yes
. 2016-01-05 15:28:34.035 TLS/SSL versions: TLSv1.0-TLSv1.2
. 2016-01-05 15:28:34.035 Local directory: C:\Users\chooks\Documents, Remote directory: /, Update: Yes, Cache: Yes
. 2016-01-05 15:28:34.035 Cache directory changes: Yes, Permanent: Yes
. 2016-01-05 15:28:34.035 Timezone offset: 0h 0m
. 2016-01-05 15:28:34.035 --------------------------------------------------------------------------
. 2016-01-05 15:28:34.113 Connecting to sftp.general-assurance.com ...
. 2016-01-05 15:28:34.113 Connected with sftp.general-assurance.com, negotiating TLS connection...
< 2016-01-05 15:28:34.113 220-FileZilla Server version 0.9.44 beta
< 2016-01-05 15:28:34.113 220-GAA FTP Server
< 2016-01-05 15:28:34.113 220 Authorized Users Only
> 2016-01-05 15:28:34.113 AUTH SSL
< 2016-01-05 15:28:35.174 234 Using authentication type SSL
. 2016-01-05 15:28:36.063 Verifying certificate for "General Assurance of America" with fingerprint f5:dd:dc:e5:10:6f:a0:dc:3a:88:de:85:79:f5:2b:a4:08:46:85:34 and 18 failures
. 2016-01-05 15:28:36.094 Certificate common name "sftp.general-assurance.com" matches hostname
. 2016-01-05 15:28:36.094 Certificate for "General Assurance of America" matches cached fingerprint and failures
. 2016-01-05 15:28:36.094 Using TLSv1.2, cipher TLSv1/SSLv3: AES256-GCM-SHA384, 1024 bit RSA
. 2016-01-05 15:28:36.110 TLS connection established. Waiting for welcome message...
> 2016-01-05 15:28:36.110 USER 7065GAA
< 2016-01-05 15:28:36.110 331 Password required for 7065gaa
> 2016-01-05 15:28:36.110 PASS ********
< 2016-01-05 15:28:36.141 230 Logged on
> 2016-01-05 15:28:36.141 SYST
< 2016-01-05 15:28:36.156 215 UNIX emulated by FileZilla
> 2016-01-05 15:28:36.156 FEAT
< 2016-01-05 15:28:36.188 211-Features:
< 2016-01-05 15:28:36.188 MDTM
< 2016-01-05 15:28:36.188 REST STREAM
< 2016-01-05 15:28:36.188 SIZE
< 2016-01-05 15:28:36.188 MLST type*;size*;modify*;
< 2016-01-05 15:28:36.188 MLSD
< 2016-01-05 15:28:36.188 AUTH SSL
< 2016-01-05 15:28:36.188 AUTH TLS
< 2016-01-05 15:28:36.188 PROT
< 2016-01-05 15:28:36.188 PBSZ
< 2016-01-05 15:28:36.188 UTF8
< 2016-01-05 15:28:36.203 CLNT
< 2016-01-05 15:28:36.203 MFMT
< 2016-01-05 15:28:36.203 211 End
> 2016-01-05 15:28:36.203 PBSZ 0
< 2016-01-05 15:28:36.203 200 PBSZ=0
> 2016-01-05 15:28:36.203 PROT P
< 2016-01-05 15:28:36.234 200 Protection level set to P
. 2016-01-05 15:28:36.297 Connected
. 2016-01-05 15:28:36.297 --------------------------------------------------------------------------
. 2016-01-05 15:28:36.297 Using FTP protocol.
. 2016-01-05 15:28:36.297 Doing startup conversation with host.
> 2016-01-05 15:28:36.359 PWD
< 2016-01-05 15:28:36.375 257 "/" is current directory.
. 2016-01-05 15:28:36.375 Changing directory to "/".
> 2016-01-05 15:28:36.375 CWD /
< 2016-01-05 15:28:36.406 250 CWD successful. "/" is current directory.
. 2016-01-05 15:28:36.406 Getting current directory name.
> 2016-01-05 15:28:36.406 PWD
< 2016-01-05 15:28:36.422 257 "/" is current directory.
. 2016-01-05 15:28:36.609 Retrieving directory listing...
> 2016-01-05 15:28:36.609 TYPE A
< 2016-01-05 15:28:36.624 200 Type set to A
> 2016-01-05 15:28:36.624 PASV
< 2016-01-05 15:28:36.656 227 Entering Passive Mode (66,129,113,165,195,125)
> 2016-01-05 15:28:36.656 MLSD
. 2016-01-05 15:28:36.656 Connecting to 66.129.113.165:50045 ...
. 2016-01-05 15:28:37.670 Transfer channel can't be opened. Reason: No connection could be made because the target machine actively refused it.
. 2016-01-05 15:28:37.670 Could not retrieve directory listing
* 2016-01-05 15:28:37.794 (ECommand) Error listing directory '/'.
* 2016-01-05 15:28:37.794 Transfer channel can't be opened. Reason: No connection could be made because the target machine actively refused it.
* 2016-01-05 15:28:37.794 Could not retrieve directory listing
. 2016-01-05 15:28:39.027 Startup conversation with host finished.
< 2016-01-05 15:28:47.451 425 Can't open data connection for transfer of "/"
. 2016-01-05 15:29:06.483 Sending dummy command to keep session alive.
> 2016-01-05 15:29:06.483 PWD
< 2016-01-05 15:29:06.998 257 "/" is current directory.
. 2016-01-05 15:29:09.650 Disconnected from server


Any Help would be appreciated. Thanks.

Start here by learning about network configuration needed for the passive FTP mode to work:
https://winscp.net/eng/docs/ftp_modes

martin wrote:

Start here by learning about network configuration needed for the passive FTP mode to work:
https://winscp.net/eng/docs/ftp_modes

This exact same setup is working from everywhere except inside this clients network. It's not a problem with the configuration that I can find. Thanks,

Josh

So it must be a local firewall or NAT in the client's network that is blocking the connection.