Error Listing Empty Directory On Complete FTP Server

Hey all! We are using Complete FTP Server as an SFTP file repository for some of our clients. We are recommending these clients use WinSCP's portable version to connect to the server. We've been having a frustrating problem however where if a client tries to enter an empty folder, an error is thrown at them as follows:

---------------------------
Error listing directory '/'.
---------------------------
Server returned empty listing for directory '/'.
---------------------------

Up until recently, this would cause the server to drop the connection. The developers of Complete FTP Server were kind enough to provide an internal update to me which prevents the disconnection but does not remove the error. They have researched the problem and claim it is a bug in WinSCP that is causing this problem as only this client has caused the issue and it has happened with several of their customers. I am running WinSCP 4.3.3. Their support representative said the following to me:

"The problem is that WinSCP sends a request to list the directory "/..", which is an invalid directory. This is clearly an error on the part of WinSCP, but CompleteFTP 5.2.1 then throws a hissy-fit and drops the connection, instead of calmly informing WinSCP of its mistake."

For now, the problem is manageable as while the error is shown, the clients are not disconnected. However, would it be possible to look into this and hopefully come up with a solution to it? I can provide the information to contact the Complete FTP Server support guys I've been dealing with on request. Should it help as well, I'll also put a WinSCP log below. Thanks very much!

. 2011-07-19 08:39:03.543 --------------------------------------------------------------------------
. 2011-07-19 08:39:03.544 WinSCP Version 4.3.3 (Build 1340) (OS 6.1.7601 Service Pack 1)
. 2011-07-19 08:39:03.545 Configuration: C:\COMSTUFF\WinSCP.ini
. 2011-07-19 08:39:03.545 Login time: July-19-11 8:39:03 AM
. 2011-07-19 08:39:03.545 --------------------------------------------------------------------------
. 2011-07-19 08:39:03.546 Session name: WESA (Stored session)
. 2011-07-19 08:39:03.546 Host name: transfers.wesa.ca (Port: 22)
. 2011-07-19 08:39:03.546 User name: (Password: No, Key file: No)
. 2011-07-19 08:39:03.546 Tunnel: No
. 2011-07-19 08:39:03.546 Transfer Protocol: SFTP
. 2011-07-19 08:39:03.547 Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
. 2011-07-19 08:39:03.547 Proxy: none
. 2011-07-19 08:39:03.547 SSH protocol version: 2; Compression: No
. 2011-07-19 08:39:03.547 Bypass authentication: No
. 2011-07-19 08:39:03.547 Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
. 2011-07-19 08:39:03.547 Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
. 2011-07-19 08:39:03.547 SSH Bugs: -,-,-,-,-,-,-,-,-
. 2011-07-19 08:39:03.547 SFTP Bugs: -,-
. 2011-07-19 08:39:03.547 Return code variable: Autodetect; Lookup user groups: Yes
. 2011-07-19 08:39:03.547 Shell: default
. 2011-07-19 08:39:03.547 EOL: 0, UTF: 2
. 2011-07-19 08:39:03.547 Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
. 2011-07-19 08:39:03.547 LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
. 2011-07-19 08:39:03.547 Local directory: default, Remote directory: home, Update: No, Cache: Yes
. 2011-07-19 08:39:03.547 Cache directory changes: Yes, Permanent: Yes
. 2011-07-19 08:39:03.547 DST mode: 1
. 2011-07-19 08:39:03.547 --------------------------------------------------------------------------
. 2011-07-19 08:39:03.632 Looking up host "transfers.wesa.ca"
. 2011-07-19 08:39:03.648 Connecting to 10.101.1.21 port 22
. 2011-07-19 08:39:03.669 Server version: SSH-2.0-CompleteFTP-5.2.1
. 2011-07-19 08:39:03.669 We believe remote version has SSH-2 ignore bug
. 2011-07-19 08:39:03.669 Using SSH protocol version 2
. 2011-07-19 08:39:03.669 We claim version: SSH-2.0-WinSCP_release_4.3.3
. 2011-07-19 08:39:03.673 Doing Diffie-Hellman group exchange
. 2011-07-19 08:39:03.819 Doing Diffie-Hellman key exchange with hash SHA-1
. 2011-07-19 08:39:04.162 Host key fingerprint is:
. 2011-07-19 08:39:04.162 ssh-rsa 1024 cf:89:84:7c:a5:7d:72:fe:b5:07:af:2a:ba:b6:86:ad
. 2011-07-19 08:39:04.162 Initialised AES-256 SDCTR client->server encryption
. 2011-07-19 08:39:04.163 Initialised HMAC-SHA1 client->server MAC algorithm
. 2011-07-19 08:39:04.165 Initialised AES-256 SDCTR server->client encryption
. 2011-07-19 08:39:04.165 Initialised HMAC-SHA1 server->client MAC algorithm
. 2011-07-19 08:39:04.207 Prompt (2, SSH login name, , login as: )
. 2011-07-19 08:39:07.347 Prompt (7, SSH password, , &Password: )
. 2011-07-19 08:39:08.848 Sent password
. 2011-07-19 08:39:08.851 Access granted
. 2011-07-19 08:39:08.855 Opened channel for session
. 2011-07-19 08:39:09.070 Started a shell/command
. 2011-07-19 08:39:09.074 --------------------------------------------------------------------------
. 2011-07-19 08:39:09.074 Using SFTP protocol.
. 2011-07-19 08:39:09.077 Doing startup conversation with host.
> 2011-07-19 08:39:09.087 Type: SSH_FXP_INIT, Size: 5, Number: -1
< 2011-07-19 08:39:09.092 Type: SSH_FXP_VERSION, Size: 5, Number: -1
. 2011-07-19 08:39:09.092 SFTP version 3 negotiated.
. 2011-07-19 08:39:09.092 We believe the server has signed timestamps bug
. 2011-07-19 08:39:09.092 We will use UTF-8 strings for status messages only
. 2011-07-19 08:39:09.103 Getting current directory name.
. 2011-07-19 08:39:09.103 Getting real path for '.'
> 2011-07-19 08:39:09.103 Type: SSH_FXP_REALPATH, Size: 10, Number: 16
< 2011-07-19 08:39:09.106 Type: SSH_FXP_NAME, Size: 77, Number: 16
. 2011-07-19 08:39:09.106 Real path is '/'
. 2011-07-19 08:39:09.106 Listing directory "/".
> 2011-07-19 08:39:09.106 Type: SSH_FXP_OPENDIR, Size: 10, Number: 267
< 2011-07-19 08:39:09.109 Type: SSH_FXP_HANDLE, Size: 19, Number: 267
> 2011-07-19 08:39:09.109 Type: SSH_FXP_READDIR, Size: 19, Number: 524
< 2011-07-19 08:39:09.112 Type: SSH_FXP_STATUS, Size: 17, Number: 524
< 2011-07-19 08:39:09.112 Status code: 1
. 2011-07-19 08:39:09.112 Listing file "/..".
> 2011-07-19 08:39:09.112 Type: SSH_FXP_LSTAT, Size: 12, Number: 775
. 2011-07-19 08:39:09.121 Received disconnect message (protocol error)
. 2011-07-19 08:39:09.121 Disconnection message text: /..
. 2011-07-19 08:39:09.122 Server sent disconnect message
. 2011-07-19 08:39:09.122 type 2 (protocol error):
. 2011-07-19 08:39:09.122 "/.."
* 2011-07-19 08:39:09.146 (ESshFatal) Server sent disconnect message
* 2011-07-19 08:39:09.147 type 2 (protocol error):
* 2011-07-19 08:39:09.147 "/.."
* 2011-07-19 08:39:09.147 Can't get attributes of file '/..'.
* 2011-07-19 08:39:09.147 Error listing directory '/'.

Thanks for your post. This issue has been added to tracker:
https://winscp.net/tracker/706

I have sent you an email with development version to test.

I am getting the following error with one of our source FTP folders (only one folder atm).

"Server returned empty listing for directory '/Output'."

I can successfully add files to the folder and download from the folder but I get this error whenever the folder is empty.

This is also occurring using the winscp .net library, development build sent to be with date 2013-09-30.

"Exception: WinSCP.SessionRemoteException: Error listing directory '/Output'. ---> WinSCP.SessionRemoteException: Server returned empty listing for directory '/Output'."

jhirst wrote:

I am getting the following error with one of our source FTP folders (only one folder atm).

"Server returned empty listing for directory '/Output'."

I can successfully add files to the folder and download from the folder but I get this error whenever the folder is empty.

Please attach a full log file showing the problem (using the latest version of WinSCP).

--------------------------------------------------------------------------
WinSCP Version 5.2.5 (Build 3610) (OS 6.3.9600 - Windows 8.1 Pro)
Configuration: HKEY_CURRENT_USER\Software\Martin Prikryl\WinSCP 2\
Local account: ***************
Working directory: C:\Program Files\WinSCP
Process ID: 6808
Command-line: "C:\Program Files\WinSCP\WinSCP.exe"
Time zone: Current: GMT+1, Standard: GMT+0, DST: GMT+1, DST Start: 30/03/2014, DST End: 26/10/2014
Login time: 13 April 2014 12:11:22
--------------------------------------------------------------------------
Session name: ***************(Site)
Host name: ***************
User name: Nimble (Password: Yes, Key file: Yes)
Tunnel: No
Transfer Protocol: SFTP (SCP)
Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
Proxy: none
SSH protocol version: 2; Compression: No
Bypass authentication: No
Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
SSH Bugs: A,A,A,A,A,A,A,A,A,A
Return code variable: Autodetect; Lookup user groups: A
Shell: default
EOL: 0, UTF: 2
Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
SFTP Bugs: A,A
SFTP Server: default
Local directory: C:\Users\Jason, Remote directory: home, Update: No, Cache: Yes
Cache directory changes: Yes, Permanent: Yes
DST mode: 1; Timezone offset: 0h 0m
--------------------------------------------------------------------------
Looking up host "***************"
Connecting to ***************
Server version: SSH-2.0-1.36 sshlib: GlobalScape
We believe remote version ignores SSH-2 maximum packet size
Using SSH protocol version 2
We claim version: SSH-2.0-WinSCP_release_5.2.5
Using Diffie-Hellman with standard group "group1"
Doing Diffie-Hellman key exchange with hash SHA-1
Verifying host key dss ***************
Host key matches cached key
Host key fingerprint is:
***************
Initialised AES-256 CBC client->server encryption
Initialised HMAC-SHA1 client->server MAC algorithm
Initialised AES-256 CBC server->client encryption
Initialised HMAC-SHA1 server->client MAC algorithm
Reading private key file "C:\Nimble\ComprehensiveCreditReport\ftpsshkey.ppk"
Using username "Nimble".
Offered public key
Offer of public key accepted
Authenticating with public key "rsa-key-20140226"
Sent public key signature
Access granted
Opened channel for session
Started a shell/command
--------------------------------------------------------------------------
Using SFTP protocol.
Doing startup conversation with host.
Type: SSH_FXP_INIT, Size: 5, Number: -1
Type: SSH_FXP_VERSION, Size: 5, Number: -1
SFTP version 3 negotiated.
We believe the server has signed timestamps bug
We will use UTF-8 strings for status messages only
Getting current directory name.
Getting real path for '.'
Type: SSH_FXP_REALPATH, Size: 10, Number: 16
Type: SSH_FXP_NAME, Size: 23, Number: 16
Real path is '/'
Listing directory "/".
Type: SSH_FXP_OPENDIR, Size: 10, Number: 267
Type: SSH_FXP_HANDLE, Size: 10, Number: 267
Type: SSH_FXP_READDIR, Size: 10, Number: 524
Type: SSH_FXP_NAME, Size: 276, Number: 524
Type: SSH_FXP_READDIR, Size: 10, Number: 780
Type: SSH_FXP_STATUS, Size: 22, Number: 780
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 1028
Input;d;0;2014-04-01T08:53:36.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-04-01T08:47:28.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Test;d;0;2014-02-26T05:25:02.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Startup conversation with host finished.
Cached directory change via "Test" to "/Test".
Getting current directory name.
Listing directory "/Test".
Type: SSH_FXP_OPENDIR, Size: 14, Number: 1291
Type: SSH_FXP_STATUS, Size: 21, Number: 1028
Discarding reserved response
Type: SSH_FXP_HANDLE, Size: 10, Number: 1291
Type: SSH_FXP_READDIR, Size: 10, Number: 1548
Type: SSH_FXP_NAME, Size: 189, Number: 1548
Type: SSH_FXP_READDIR, Size: 10, Number: 1804
Type: SSH_FXP_STATUS, Size: 22, Number: 1804
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 2052
Input;d;0;2014-03-31T04:03:55.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-03-31T04:13:16.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Cached directory change via "Input" to "/Test/Input".
Getting current directory name.
Listing directory "/Test/Input".
Type: SSH_FXP_OPENDIR, Size: 20, Number: 2315
Type: SSH_FXP_STATUS, Size: 21, Number: 2052
Discarding reserved response
Type: SSH_FXP_HANDLE, Size: 10, Number: 2315
Type: SSH_FXP_READDIR, Size: 10, Number: 2572
Type: SSH_FXP_NAME, Size: 102, Number: 2572
Type: SSH_FXP_READDIR, Size: 10, Number: 2828
Type: SSH_FXP_STATUS, Size: 22, Number: 2828
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 3076
Archive;d;0;2014-03-31T04:03:56.000Z;"user" [0];"group" [0];rwxrw-rw-;1

Well, I believe the message is correct. I do not think WinSCP can do any better. Do you get other results with other SFTP clients?

I haven't tried another ftp client.
Why would this cause an Exception though?
I am using WinSCP for two other systems and I do not get this Exception when checking other folders.
In fact using the same ftp site and checking the /Input/ folder I don't get this Exception I simply see an empty folder.

jhirst wrote:

In fact using the same ftp site and checking the /Input/ folder I don't get this Exception I simply see an empty folder.

Post a log file for that for comparison.

--------------------------------------------------------------------------
WinSCP Version 5.2.5 (Build 3610) (OS 6.3.9600 - Windows 8.1 Pro)
Configuration: HKEY_CURRENT_USER\Software\Martin Prikryl\WinSCP 2\
Local account: ****************
Working directory: C:\Program Files\WinSCP
Process ID: 6808
Command-line: "C:\Program Files\WinSCP\WinSCP.exe"
Time zone: Current: GMT+1, Standard: GMT+0, DST: GMT+1, DST Start: 30/03/2014, DST End: 26/10/2014
Login time: 13 April 2014 12:11:22
--------------------------------------------------------------------------
Session name: ****************(Site)
Host name: ****************
User name: Nimble (Password: Yes, Key file: Yes)
Tunnel: No
Transfer Protocol: SFTP (SCP)
Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
Proxy: none
SSH protocol version: 2; Compression: No
Bypass authentication: No
Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
SSH Bugs: A,A,A,A,A,A,A,A,A,A
Return code variable: Autodetect; Lookup user groups: A
Shell: default
EOL: 0, UTF: 2
Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
SFTP Bugs: A,A
SFTP Server: default
Local directory: C:\Users\Jason, Remote directory: home, Update: No, Cache: Yes
Cache directory changes: Yes, Permanent: Yes
DST mode: 1; Timezone offset: 0h 0m
--------------------------------------------------------------------------
Looking up host "****************"
Connecting to ****************
Server version: SSH-2.0-1.36 sshlib: GlobalScape
We believe remote version ignores SSH-2 maximum packet size
Using SSH protocol version 2
We claim version: SSH-2.0-WinSCP_release_5.2.5
Using Diffie-Hellman with standard group "group1"
Doing Diffie-Hellman key exchange with hash SHA-1
Verifying host key dss ****************
Host key matches cached key
Host key fingerprint is:
****************
Initialised AES-256 CBC client->server encryption
Initialised HMAC-SHA1 client->server MAC algorithm
Initialised AES-256 CBC server->client encryption
Initialised HMAC-SHA1 server->client MAC algorithm
Reading private key file "C:\Nimble\ComprehensiveCreditReport\ftpsshkey.ppk"
Using username "Nimble".
Offered public key
Offer of public key accepted
Authenticating with public key "rsa-key-20140226"
Sent public key signature
Access granted
Opened channel for session
Started a shell/command
--------------------------------------------------------------------------
Using SFTP protocol.
Doing startup conversation with host.
Type: SSH_FXP_INIT, Size: 5, Number: -1
Type: SSH_FXP_VERSION, Size: 5, Number: -1
SFTP version 3 negotiated.
We believe the server has signed timestamps bug
We will use UTF-8 strings for status messages only
Getting current directory name.
Getting real path for '.'
Type: SSH_FXP_REALPATH, Size: 10, Number: 16
Type: SSH_FXP_NAME, Size: 23, Number: 16
Real path is '/'
Listing directory "/".
Type: SSH_FXP_OPENDIR, Size: 10, Number: 267
Type: SSH_FXP_HANDLE, Size: 10, Number: 267
Type: SSH_FXP_READDIR, Size: 10, Number: 524
Type: SSH_FXP_NAME, Size: 276, Number: 524
Type: SSH_FXP_READDIR, Size: 10, Number: 780
Type: SSH_FXP_STATUS, Size: 22, Number: 780
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 1028
Input;d;0;2014-04-01T08:53:36.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-04-01T08:47:28.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Test;d;0;2014-02-26T05:25:02.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Startup conversation with host finished.
Cached directory change via "Test" to "/Test".
Getting current directory name.
Listing directory "/Test".
Type: SSH_FXP_OPENDIR, Size: 14, Number: 1291
Type: SSH_FXP_STATUS, Size: 21, Number: 1028
Discarding reserved response
Type: SSH_FXP_HANDLE, Size: 10, Number: 1291
Type: SSH_FXP_READDIR, Size: 10, Number: 1548
Type: SSH_FXP_NAME, Size: 189, Number: 1548
Type: SSH_FXP_READDIR, Size: 10, Number: 1804
Type: SSH_FXP_STATUS, Size: 22, Number: 1804
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 2052
Input;d;0;2014-03-31T04:03:55.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-03-31T04:13:16.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Cached directory change via "Input" to "/Test/Input".
Getting current directory name.
Listing directory "/Test/Input".
Type: SSH_FXP_OPENDIR, Size: 20, Number: 2315
Type: SSH_FXP_STATUS, Size: 21, Number: 2052
Discarding reserved response
Type: SSH_FXP_HANDLE, Size: 10, Number: 2315
Type: SSH_FXP_READDIR, Size: 10, Number: 2572
Type: SSH_FXP_NAME, Size: 102, Number: 2572
Type: SSH_FXP_READDIR, Size: 10, Number: 2828
Type: SSH_FXP_STATUS, Size: 22, Number: 2828
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 3076
Archive;d;0;2014-03-31T04:03:56.000Z;"user" [0];"group" [0];rwxrw-rw-;1

Thanks for the new log. Though you have replaced the old log too and I do not have a copy, so I cannot compare them. Please make sure both log for Output and Input is available.

Sorry, here's the failure log:

--------------------------------------------------------------------------
WinSCP Version 5.2.5 (Build 3610) (OS 6.3.9600 - Windows 8.1 Pro)
Configuration: HKEY_CURRENT_USER\Software\Martin Prikryl\WinSCP 2\
Local account: ***************
Working directory: C:\Program Files\WinSCP
Process ID: 9912
Command-line: "C:\Program Files\WinSCP\WinSCP.exe"
Time zone: Current: GMT+1, Standard: GMT+0, DST: GMT+1, DST Start: 30/03/2014, DST End: 26/10/2014
Login time: 14 April 2014 09:47:04
--------------------------------------------------------------------------
Session name: ***************(Site)
Host name: ***************
User name: Nimble (Password: Yes, Key file: Yes)
Tunnel: No
Transfer Protocol: SFTP (SCP)
Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
Proxy: none
SSH protocol version: 2; Compression: No
Bypass authentication: No
Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
SSH Bugs: A,A,A,A,A,A,A,A,A,A
Return code variable: Autodetect; Lookup user groups: A
Shell: default
EOL: 0, UTF: 2
Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
SFTP Bugs: A,A
SFTP Server: default
Local directory: C:\Users\Jason, Remote directory: home, Update: No, Cache: Yes
Cache directory changes: Yes, Permanent: Yes
DST mode: 1; Timezone offset: 0h 0m
--------------------------------------------------------------------------
Looking up host "***************"
Connecting to ***************
Server version: SSH-2.0-1.36 sshlib: GlobalScape
We believe remote version ignores SSH-2 maximum packet size
Using SSH protocol version 2
We claim version: SSH-2.0-WinSCP_release_5.2.5
Using Diffie-Hellman with standard group "group1"
Doing Diffie-Hellman key exchange with hash SHA-1
Verifying host key dss ***************
Host key matches cached key
Host key fingerprint is:
***************
Initialised AES-256 CBC client->server encryption
Initialised HMAC-SHA1 client->server MAC algorithm
Initialised AES-256 CBC server->client encryption
Initialised HMAC-SHA1 server->client MAC algorithm
Reading private key file "C:\Nimble\ComprehensiveCreditReport\ftpsshkey.ppk"
Using username "Nimble".
Offered public key
Offer of public key accepted
Authenticating with public key "rsa-key-20140226"
Sent public key signature
Access granted
Opened channel for session
Started a shell/command
--------------------------------------------------------------------------
Using SFTP protocol.
Doing startup conversation with host.
Type: SSH_FXP_INIT, Size: 5, Number: -1
Type: SSH_FXP_VERSION, Size: 5, Number: -1
SFTP version 3 negotiated.
We believe the server has signed timestamps bug
We will use UTF-8 strings for status messages only
Getting current directory name.
Getting real path for '.'
Type: SSH_FXP_REALPATH, Size: 10, Number: 16
Type: SSH_FXP_NAME, Size: 23, Number: 16
Real path is '/'
Listing directory "/".
Type: SSH_FXP_OPENDIR, Size: 10, Number: 267
Type: SSH_FXP_HANDLE, Size: 10, Number: 267
Type: SSH_FXP_READDIR, Size: 10, Number: 524
Type: SSH_FXP_NAME, Size: 276, Number: 524
Type: SSH_FXP_READDIR, Size: 10, Number: 780
Type: SSH_FXP_STATUS, Size: 22, Number: 780
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 1028
Input;d;0;2014-04-01T08:53:36.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-04-01T08:47:28.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Test;d;0;2014-02-26T05:25:02.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Startup conversation with host finished.
Cached directory change via "Output" to "/Output".
Getting current directory name.
Listing directory "/Output".
Type: SSH_FXP_OPENDIR, Size: 16, Number: 1291
Type: SSH_FXP_STATUS, Size: 21, Number: 1028
Discarding reserved response
Type: SSH_FXP_HANDLE, Size: 10, Number: 1291
Type: SSH_FXP_READDIR, Size: 10, Number: 1548
Type: SSH_FXP_STATUS, Size: 22, Number: 1548
Status code: 1
Listing file "/Output/..".
Type: SSH_FXP_LSTAT, Size: 19, Number: 1799
Type: SSH_FXP_STATUS, Size: 33, Number: 1799
Status code: 2, Message: 1799, Server: File not found, Language: en
Type: SSH_FXP_CLOSE, Size: 10, Number: 2052
(ECommand) Error listing directory '/Output'.
Server returned empty listing for directory '/Output'.

But the /Test/Input folder is not empty, it includes subdirectory Archive:

Archive;d;0;2014-03-31T04:03:56.000Z;"user" [0];"group" [0];rwxrw-rw-;1

Well this Test\Output folder is empty:

--------------------------------------------------------------------------
WinSCP Version 5.2.5 (Build 3610) (OS 6.3.9600 - Windows 8.1 Pro)
Configuration: HKEY_CURRENT_USER\Software\Martin Prikryl\WinSCP 2\
Local account: *************
Working directory: C:\Program Files\WinSCP
Process ID: 4064
Command-line: "C:\Program Files\WinSCP\WinSCP.exe"
Time zone: Current: GMT+1, Standard: GMT+0, DST: GMT+1, DST Start: 30/03/2014, DST End: 26/10/2014
Login time: 17 April 2014 09:41:32
--------------------------------------------------------------------------
Session name: *************(Site)
Host name: *************
User name: Nimble (Password: Yes, Key file: Yes)
Tunnel: No
Transfer Protocol: SFTP (SCP)
Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
Proxy: none
SSH protocol version: 2; Compression: No
Bypass authentication: No
Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
SSH Bugs: A,A,A,A,A,A,A,A,A,A
Return code variable: Autodetect; Lookup user groups: A
Shell: default
EOL: 0, UTF: 2
Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
SFTP Bugs: A,A
SFTP Server: default
Local directory: C:\Users\Jason, Remote directory: home, Update: No, Cache: Yes
Cache directory changes: Yes, Permanent: Yes
DST mode: 1; Timezone offset: 0h 0m
--------------------------------------------------------------------------
Looking up host "*************"
Connecting to *************
Server version: SSH-2.0-1.36 sshlib: GlobalScape
We believe remote version ignores SSH-2 maximum packet size
Using SSH protocol version 2
We claim version: SSH-2.0-WinSCP_release_5.2.5
Using Diffie-Hellman with standard group "group1"
Doing Diffie-Hellman key exchange with hash SHA-1
Verifying host key dss *************
Host key matches cached key
Host key fingerprint is:
*************
Initialised AES-256 CBC client->server encryption
Initialised HMAC-SHA1 client->server MAC algorithm
Initialised AES-256 CBC server->client encryption
Initialised HMAC-SHA1 server->client MAC algorithm
Reading private key file "C:\Nimble\ComprehensiveCreditReport\ftpsshkey.ppk"
Using username "Nimble".
Offered public key
Offer of public key accepted
Authenticating with public key "rsa-key-20140226"
Sent public key signature
Access granted
Opened channel for session
Started a shell/command
--------------------------------------------------------------------------
Using SFTP protocol.
Doing startup conversation with host.
Type: SSH_FXP_INIT, Size: 5, Number: -1
Type: SSH_FXP_VERSION, Size: 5, Number: -1
SFTP version 3 negotiated.
We believe the server has signed timestamps bug
We will use UTF-8 strings for status messages only
Getting current directory name.
Getting real path for '.'
Type: SSH_FXP_REALPATH, Size: 10, Number: 16
Type: SSH_FXP_NAME, Size: 23, Number: 16
Real path is '/'
Listing directory "/".
Type: SSH_FXP_OPENDIR, Size: 10, Number: 267
Type: SSH_FXP_HANDLE, Size: 10, Number: 267
Type: SSH_FXP_READDIR, Size: 10, Number: 524
Type: SSH_FXP_NAME, Size: 276, Number: 524
Type: SSH_FXP_READDIR, Size: 10, Number: 780
Type: SSH_FXP_STATUS, Size: 22, Number: 780
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 1028
Input;d;0;2014-04-01T08:53:36.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-04-01T08:47:28.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Test;d;0;2014-02-26T05:25:02.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Startup conversation with host finished.
Cached directory change via "Test" to "/Test".
Getting current directory name.
Listing directory "/Test".
Type: SSH_FXP_OPENDIR, Size: 14, Number: 1291
Type: SSH_FXP_STATUS, Size: 21, Number: 1028
Discarding reserved response
Type: SSH_FXP_HANDLE, Size: 10, Number: 1291
Type: SSH_FXP_READDIR, Size: 10, Number: 1548
Type: SSH_FXP_NAME, Size: 189, Number: 1548
Type: SSH_FXP_READDIR, Size: 10, Number: 1804
Type: SSH_FXP_STATUS, Size: 22, Number: 1804
Status code: 1
Type: SSH_FXP_CLOSE, Size: 10, Number: 2052
Input;d;0;2014-04-16T16:02:13.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Output;d;0;2014-04-16T16:03:50.000Z;"user" [0];"group" [0];rwxrw-rw-;1
Changing directory to "Output".
Getting real path for '/Test/Output'
Type: SSH_FXP_REALPATH, Size: 21, Number: 2320
Type: SSH_FXP_STATUS, Size: 21, Number: 2052
Discarding reserved response
Type: SSH_FXP_NAME, Size: 45, Number: 2320
Real path is '/Test/Output'
Trying to open directory "/Test/Output".
Type: SSH_FXP_LSTAT, Size: 21, Number: 2567
Type: SSH_FXP_ATTRS, Size: 21, Number: 2567
Getting current directory name.
Listing directory "/Test/Output".
Type: SSH_FXP_OPENDIR, Size: 21, Number: 2827
Type: SSH_FXP_HANDLE, Size: 10, Number: 2827
Type: SSH_FXP_READDIR, Size: 10, Number: 3084
Type: SSH_FXP_STATUS, Size: 22, Number: 3084
Status code: 1
Listing file "/Test/Output/..".
Type: SSH_FXP_LSTAT, Size: 24, Number: 3335
Type: SSH_FXP_ATTRS, Size: 21, Number: 3335
..;D;0;2014-02-26T05:25:02.000Z;"" [0];"" [0];rwxrw-rw-;1
Type: SSH_FXP_CLOSE, Size: 10, Number: 3588
..;D;0;2014-02-26T05:25:02.000Z;"" [0];"" [0];rwxrw-rw-;1

Yes, in both cases the directory is empty. In both cases the server returns empty listing, lacking even a common . and .. entries. In such case, WinSCP tries to explicitly retrieve data about parent directory. But while reading data about /Test/Output/.. succeeds, reading data about /Output/.. fails.