I was testing SFTP transfers and saw this error message get logged:
ERROR [SFTPSubsystem] 13 Feb 2015 16:44:08.887 : VerifyRequestOK: Operation unsupported
Tried to look this up but didn't find anything useful. Oddly, the file was still successfully uploaded, even with this error.
I set the logging level higher and this is what it showed me.
DEBUG [ClientKeyExchanger] 13 Feb 2015 16:53:54.468 : Processed SSH_MSG_KEXDH_INIT reply successfully
DEBUG [ClientKeyExchanger] 13 Feb 2015 16:53:54.468 : Sending SSH_MSG_NEWKEYS
DEBUG [ClientKeyExchanger] 13 Feb 2015 16:53:54.468 : Sent SSH_MSG_NEWKEYS
DEBUG [ClientKeyExchanger] 13 Feb 2015 16:53:54.468 : Established ciphers
DEBUG [ClientKeyExchanger] 13 Feb 2015 16:53:54.468 : Established MACs
DEBUG [ClientKeyExchanger] 13 Feb 2015 16:53:54.468 : Reading SSH_MSG_NEWKEYS reply
DEBUG [AbstractKeyExchanger] 13 Feb 2015 16:53:54.483 : Processing SSH_MSG_NEWKEYS reply
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Processed 0 queued messages
DEBUG [AbstractKeyExchanger] 13 Feb 2015 16:53:54.483 : Processed SSH_MSG_NEWKEYS reply
INFO [AbstractKeyExchanger] 13 Feb 2015 16:53:54.483 : Negotiated new keys successfully
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Key exchange complete
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Sent SSH_MSG_SERVICE_REQUEST 'ssh-userauth'
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Waiting for packet
DEBUG [PlainSocket] 13 Feb 2015 16:53:54.483 : FTPConnection.2 RepeatCallback received 52 bytes
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Packet arrived
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Starting user authentication for 'sitsftptest'
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Password authentication
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Sent SSH_MSG_USERAUTH_REQUEST
DEBUG [SSH2Connection] 13 Feb 2015 16:53:54.483 : Waiting for packet
DEBUG [PlainSocket] 13 Feb 2015 16:53:59.179 : FTPConnection.2 RepeatCallback received 36 bytes
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.179 : Packet arrived
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.179 : ProcessAuthenticationResponse: SSH_MSG_USERAUTH_SUCCESS
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.179 : User authentication successful
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.179 : Sent SSH_MSG_CHANNEL_OPEN
DEBUG [PlainSocket] 13 Feb 2015 16:53:59.179 : FTPConnection.2 RepeatCallback received 52 bytes
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.179 : FTPConnection.2 ProcessPacket pt=SSH_MSG_CHANNEL_OPEN_CONFIRMATION
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 ProcessPacket: status= 2, pt=SSH_MSG_CHANNEL_OPEN_CONFIRMATION
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 OpenSFTP pt=SSH_MSG_CHANNEL_OPEN_CONFIRMATION
DEBUG [ChannelDataWindow] 13 Feb 2015 16:53:59.179 : FTPConnection.2 Remote window size set to 16384
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 Remote max packet size=35840
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 Setting packet size=35840
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 Sending SSH_MSG_CHANNEL_REQUEST
INFO [SSHFTPClient] 13 Feb 2015 16:53:59.179 : Waiting for SSH channel to be opened
DEBUG [PlainSocket] 13 Feb 2015 16:53:59.179 : FTPConnection.2 RepeatCallback received 36 bytes
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.179 : FTPConnection.2 ProcessPacket pt=SSH_MSG_CHANNEL_SUCCESS
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 ProcessPacket: status= 1, pt=SSH_MSG_CHANNEL_SUCCESS
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.179 : FTPConnection.2 OpenSFTP pt=SSH_MSG_CHANNEL_SUCCESS
DEBUG [SSHFTPClient] 13 Feb 2015 16:53:59.195 : SSH channel opened
INFO [SFTPSubsystem] 13 Feb 2015 16:53:59.195 : Initialize(): client version: 3
ALL [SFTPMessage] 13 Feb 2015 16:53:59.195 : Send : Name=SSH_FXP_INIT,Type=1,RequestID=0
version=3
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.195 : Transmit 9 bytes
DEBUG [ChannelDataWindow] 13 Feb 2015 16:53:59.195 : Remote window size decreased to 16375
DEBUG [PlainSocket] 13 Feb 2015 16:53:59.195 : FTPConnection.2 RepeatCallback received 52 bytes
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.195 : FTPConnection.2 ProcessPacket pt=SSH_MSG_CHANNEL_DATA
DEBUG [SSHChannel] 13 Feb 2015 16:53:59.195 : FTPConnection.2 Channel 0: sent SSH_MSG_CHANNEL_WINDOW_ADJUST
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.195 : FTPConnection.2 Local window size increased to 1048575
ALL [SFTPMessageProcessor] 13 Feb 2015 16:53:59.195 : FTPConnection.2 NextMessageLength=5
DEBUG [SFTPMessageFactory] 13 Feb 2015 16:53:59.195 : FTPConnection.2 Received message (type=2,len=5)
DEBUG [SFTPMessageStore] 13 Feb 2015 16:53:59.195 : FTPConnection.2 AddMessage(0) - added to store
ALL [SFTPMessage] 13 Feb 2015 16:53:59.195 : Reply : Name=SSH_FXP_VERSION,Type=2,RequestID=0
version=3
extension count=0
INFO [SFTPSubsystem] 13 Feb 2015 16:53:59.195 : Server SFTP version: 3
DEBUG [SFTPSubsystem] 13 Feb 2015 16:53:59.195 : SFTP subsystem started
DEBUG [SSHFTPClient] 13 Feb 2015 16:53:59.195 : Connect() succeeded
ALL [SFTPMessage] 13 Feb 2015 16:53:59.195 : Send : Name=SSH_FXP_REALPATH,Type=16,RequestID=1
originalPath=.
DEBUG [SSH2Channel] 13 Feb 2015 16:53:59.195 : Transmit 14 bytes
DEBUG [ChannelDataWindow] 13 Feb 2015 16:53:59.195 : Remote window size decreased to 16361
DEBUG [PlainSocket] 13 Feb 2015 16:53:59.210 : FTPConnection.2 RepeatCallback received 124 bytes
DEBUG [SSH2Connection] 13 Feb 2015 16:53:59.210 : FTPConnection.2 ProcessPacket pt=SSH_MSG_CHANNEL_DATA
ALL [SFTPMessageProcessor] 13 Feb 2015 16:53:59.210 : FTPConnection.2 NextMessageLength=81
DEBUG [SFTPMessageFactory] 13 Feb 2015 16:53:59.210 : FTPConnection.2 Received message (type=104,len=81)
DEBUG [SFTPMessage] 13 Feb 2015 16:53:59.210 : FTPConnection.2 SSH_FXP_NAME: requestID=1, 1 files
ALL [SFTPMessage] 13 Feb 2015 16:53:59.210 : FTPConnection.2 count=0,short=/Home/InstitutionD/sitsftptest
ALL [SFTPMessage] 13 Feb 2015 16:53:59.210 : FTPConnection.2 count=0,long=/Home/InstitutionD/sitsftptest
ALL [SFTPFileAttributes] 13 Feb 2015 16:53:59.210 : FTPConnection.2 flags=0
DEBUG [SFTPMessageStore] 13 Feb 2015 16:53:59.210 : FTPConnection.2 AddMessage(1) - added to store
ALL [SFTPMessage] 13 Feb 2015 16:53:59.210 : Reply : Name=SSH_FXP_NAME,Type=104,RequestID=1
sitsftptest [AP=/Home/InstitutionD/sitsftptest, O=False, Valid flags=0, US=, G=, D=False, F=False, LI=False, R=False, W=False, AT=0, AD=1/1/1970 12:00:00 AM, MT=0, MD=1/1/1970 12:00:00 AM, P=0, S=0, U=, LN=/Home/InstitutionD/sitsftptest]
INFO [FTPConnection] 13 Feb 2015 16:53:59.210 : Auto FEAT disabled
DEBUG [SSHFTPClient] 13 Feb 2015 16:53:59.210 : Set transfer type = ASCII
DEBUG [FTPConnection] 13 Feb 2015 16:53:59.210 : Home directory is '/Home/InstitutionD/sitsftptest'
DEBUG [ExFTPConnection] 13 Feb 2015 16:53:59.210 : Attempt 1: RegularSFTP20150213.txt Overwrite
DEBUG [FTPConnection] 13 Feb 2015 16:53:59.210 : UploadFile(D:\iPass DLLs\iPayNet\FileTransferFunctionalityTests\UploadFiles\RegularSFTP.txt,RegularSFTP20150213.txt,Overwrite)
DEBUG [SSHFTPClient] 13 Feb 2015 16:53:59.210 : Put(D:\iPass DLLs\iPayNet\FileTransferFunctionalityTests\UploadFiles\RegularSFTP.txt,RegularSFTP20150213.txt)
DEBUG [SSHFTPClient] 13 Feb 2015 16:53:59.226 : ResolveRemotePath('RegularSFTP20150213.txt'); [cwd='/Home/InstitutionD/sitsftptest']
DEBUG [SSHFTPClient] 13 Feb 2015 16:53:59.226 : Resolved to '/Home/InstitutionD/sitsftptest/RegularSFTP20150213.txt'
DEBUG [SFTPSubsystem] 13 Feb 2015 16:53:59.226 : Ge
