No idea, sorry.

I get this error with Go's sftp package, where I originally posted an issue. However I have since tested with psftp and it transferred a file with no issues, so I suspect the problem is in WinSCP.

The code for my server is here (sorry it's a bit crap).

The log from WinSCP is below. I tried both the suggested 'bugs' workarounds in the WinSCP wiki; neither worked. Anyone have any ideas?

> 2016-08-15 13:41:53.020 9C,24,98,00,00,00,48,89,9C,24,A0,00,00,00,48,8B,9C,24,D0,01,00,00,48,8B,6B,
> 2016-08-15 13:41:53.020 48,48,89,6C,24,58,48,8B,9C,24,D8,01,00,00,48,8B,6B,18,48,89,6C,24,50,48,8D,
> 2016-08-15 13:41:53.020 BC,24,00,01,00,00,0F,57,C0,E8,58,A3,FC,FF,0F,11,47,F8,48,8D,9C,24,00,01,00,
> 2016-08-15 13:41:53.020 00,48,89,1C,24,48,C7,44,24,08,C8,00,00,00,C7,44,24,10,03,00,00,00,E8,3B,A4,
> 2016-08-15 13:41:53.020 FA,FF,48,8D,AC,24,00,01,00,00,48,89,2C,24,48,8B,6C,24,48,48,89,6C,24,08,48,
> 2016-08-15 13:41:53.020 8D,AC,24,98,00,00,00,48,89,6C,24,10,E8,43,A7,FA,FF,0F,B6,5C,24,18,80,FB,00,
> 2016-08-15 13:41:53.020 0F,84,B4,00,00,00,48,8B,9C,24,98,00,00,00,48,89,5C,24,68,48,8B,9C,24,A0,00,
> 2016-08-15 13:41:53.020 00,00,48,89,5C,24,70,C6,44,24,3F,01,48,8B,44,24,48,48,8D,1D,BA,45,4B,00,48,
> 2016-08-15 13:41:53.020 89,1C,24,48,8D,1D,CF,9A,20,00,48,89,9C,24,A8,00,00,00,48,89,5C,24,08,48,89,
> 2016-08-15 13:41:53.020 84,24,B0,00,00,00,48,89,44,24,10,E8,30,D8,08,00,80,7C,24,3F,00,74,36,48,8B,
> 2016-08-15 13:41:53.020 44,24,40,48,8D,1D,FD,45,4B,00,48,89,1C,24,48,8D,1D,D2,FE,29,00,48,89,9C,24,
> 2016-08-15 13:41:53.020 A8,00,00,00,48,89,5C,24,08,48,89,84,24,B0,00,00,00,48,89,44,24,10,E8,F3,D7,
> 2016-08-15 13:41:53.020 08,00,48,8B,5C,24,68,48,89,9C,24,00,02,00,00,48,8B,5C,24,70,48,89,9C,24,08,
> 2016-08-15 13:41:53.020 02,00,00,48,81,C4,C8,01,00,00,C3,48,8D,AC,24,00,01,00,00,48,89,2C,24,48,8B,
> 2016-08-15 13:41:53.020 6C,24,58,48,89,6C,24,08,48,C7,44,24,10,00,00,00,00,E8,5D,A6,FA,FF,0F,B6,5C,
> 2016-08-15 13:41:53.020 24,18,80,FB,00,74,26,48,8B,1D,8C,B4,4B,00,48,89,9C,24,00,02,00,00,48,8B,1D,
> 2016-08-15 13:41:53.020 85,B4,4B,00,48,89,9C,24,08,02,00,00,48,81,C4,C8,01,00,00,C3,48,8D,AC,24,00,
> 2016-08-15 13:41:53.020 01,00,00,48,89,2C,24,48,8B,6C,24,50,48,89,6C,24,08,48,C7,44,24,10,00,00,00,
> 2016-08-15 13:41:53.020 00,E8,09,A6,FA,FF,0F,B6,5C,24,18,80,FB,00,0F,84,8D,00,00,00,31,DB,48,89,9C,
> 2016-08-15 13:41:53.020 24,88,00,00,00,48,89,9C,24,90,00,00,00,48,8D,2D,B2,99,20,00,48,89,2C,24,48,
> 2016-08-15 13:41:53.020 8D,AC,24,88,00,00,00,48,89,6C,24,08,48,8B,6C,24,48,48,89,6C,24,10,E8,32,2B,
> 2016-08-15 13:41:53.020 F7,FF,0F,B6,5C,24,18,80,FB,00,74,24,48,8B,9C,24,88,00,00,00,48,89,5C,24,68,
> 2016-08-15 13:41:53.020 48,8B,9C,24,90,00,00,00,48,89,5C,24,70,C6,44,24,3F,01,E9,7E,FE,FF,FF,48,8B,
> 2016-08-15 13:41:53.020 1D,BD,B4,4B,00,48,89,9C,24,00,02,00,00,48,
. 2016-08-15 13:41:53.023 Sent 32768 bytes
. 2016-08-15 13:41:53.023 There are 0 bytes remaining in the send buffer
. 2016-08-15 13:41:53.023 Looking for network events
. 2016-08-15 13:41:53.023 Detected network event
. 2016-08-15 13:41:53.023 Enumerating network events for socket 1224
. 2016-08-15 13:41:53.023 Enumerated 1 network events making 1 cumulative events for socket 1224
. 2016-08-15 13:41:53.023 Handling network read event on socket 1224 with error 0
. 2016-08-15 13:41:53.023 Received 4 bytes (0)
. 2016-08-15 13:41:53.023 Received 17 bytes (0)
. 2016-08-15 13:41:53.023 Read 4 bytes (17 pending)
. 2016-08-15 13:41:53.023 Read 17 bytes (0 pending)
< 2016-08-15 13:41:53.023 Type: SSH_FXP_STATUS, Size: 17, Number: 186374
< 2016-08-15 13:41:53.023 65,00,02,D8,06,00,00,00,00,00,00,00,00,00,00,00,00,
< 2016-08-15 13:41:53.023 Status code: 0
. 2016-08-15 13:41:53.023 Received 4 bytes (0)
. 2016-08-15 13:41:53.023 Received 17 bytes (0)
. 2016-08-15 13:41:53.023 Read 4 bytes (17 pending)
. 2016-08-15 13:41:53.023 Read 17 bytes (0 pending)
< 2016-08-15 13:41:53.023 Type: SSH_FXP_STATUS, Size: 17, Number: 186630
< 2016-08-15 13:41:53.023 65,00,02,D9,06,00,00,00,00,00,00,00,00,00,00,00,00,
< 2016-08-15 13:41:53.023 Status code: 0
. 2016-08-15 13:41:53.024 Write request offset: 597548, len: 32742
> 2016-08-15 13:41:53.024 Type: SSH_FXP_WRITE, Size: 32764, Number: 188934
> 2016-08-15 13:41:53.035 06,00,02,E2,06,00,00,00,01,33,00,00,00,00,00,09,1E,2C,00,00,7F,E6,8B,1D,B6,
> 2016-08-15 13:41:53.036 B4,4B,00,48,89,9C,24,08,02,00,00,48,81,C4,C8,01,00,00,C3,48,8D,9C,24,00,01,
> 2016-08-15 13:41:53.036 00,00,48,89,1C,24,E8,2D,AA,FA,FF,0F,0B,48,8D,1D,64,FD,29,00,48,89,1C,24,48,
> 2016-08-15 13:41:53.036 8D,1D,79,1E,28,00,48,89,5C,24,08,48,8D,1D,CD,82,4D,00,48,89,5C,24,10,E8,33,
> 2016-08-15 13:41:53.036 AD,F7,FF,48,8B,44,24,18,E9,BB,FC,FF,FF,4D,8D,40,08,4C,89,04,24,48,89,74,24,
> 2016-08-15 13:41:53.036 08,E8,B7,EB,F7,FF,4C,8B,44,24,40,E9,66,FC,FF,FF,41,89,00,E9,18,FC,FF,FF,48,
> 2016-08-15 13:41:53.036 89,0C,24,48,89,6C,24,08,4C,8D,05,C5,3A,21,00,4C,89,44,24,10,E8,9B,AF,F7,FF,
> 2016-08-15 13:41:53.036 0F,0B,48,89,0C,24,48,89,6C,24,08,4C,8D,05,A9,3A,21,00,4C,89,44,24,10,E8,7F,
.....
> 2016-08-15 13:41:53.100 89,8C,24,88,00,00,00,48,8B,44,24,60,48,83,F8,0A,7C,54,48,83,F8,0A,0F,85,9E,
> 2016-08-15 13:41:53.100 03,00,00,48,89,0C,24,48,89,84,24,90,00,00,00,48,89,44,24,08,48,8D,2D,3A,15,
> 2016-08-15 13:41:53.100 30,00,48,89,6C,24,10,48,C7,44,24,18,0A,00,00,00,E8,87,9A,FB,FF,48,8B,8C,24,
> 2016-08-15 13:41:53.100 88,00,00,00,48,8B,84,24,90,00,00,00,48,8B,5C,24,20,48,83,FB,00,0F,8F,54,03,
> 2016-08-15 13:41:53.100 00,00,48,83,F8,04,0F,85,FA,01,00,00,48,89,0C,24,48,89,84,24,90,00,00,00,48,
> 2016-08-15 13:41:53.100 89,44,24,08,48,8D,2D,C6,87,2F,00,48,89,6C,24,10,48,C7,44,24,18,04,00,00,00,
> 2016-08-15 13:41:53.100 E8,C3,98,FB,FF,48,8B,8C,24,88,00,00,00,48,8B,84,24,90,00,00,00,0F,B6,5C,24,
> 2016-08-15 13:41:53.100 20,80,FB,00,0F,84,B1,01,00,00,48,8D,9C,24,C8,00,00,00,48,89,1C,24,E8,A4,79,
> 2016-08-15 13:41:53.100 F6,FF,48,8B,9C,24,C8,00,00,00,31,ED,48,39,
. 2016-08-15 13:41:53.102 Sent 32768 bytes
. 2016-08-15 13:41:53.102 There are 0 bytes remaining in the send buffer
. 2016-08-15 13:41:53.102 Looking for network events
. 2016-08-15 13:41:53.102 Detected network event
. 2016-08-15 13:41:53.102 Enumerating network events for socket 1224
. 2016-08-15 13:41:53.102 Enumerated 1 network events making 1 cumulative events for socket 1224
. 2016-08-15 13:41:53.102 Handling network read event on socket 1224 with error 0
. 2016-08-15 13:41:53.102 Received 4 bytes (0)
. 2016-08-15 13:41:53.102 Received 17 bytes (0)
. 2016-08-15 13:41:53.102 Read 4 bytes (17 pending)
. 2016-08-15 13:41:53.102 Read 17 bytes (0 pending)
< 2016-08-15 13:41:53.102 Type: SSH_FXP_STATUS, Size: 17, Number: 186886
< 2016-08-15 13:41:53.102 65,00,02,DA,06,00,00,00,00,00,00,00,00,00,00,00,00,
< 2016-08-15 13:41:53.102 Status code: 0
. 2016-08-15 13:41:53.103 Received 4 bytes (0)
. 2016-08-15 13:41:53.103 Received 17 bytes (0)
. 2016-08-15 13:41:53.103 Read 4 bytes (17 pending)
. 2016-08-15 13:41:53.103 Read 17 bytes (0 pending)
< 2016-08-15 13:41:53.103 Type: SSH_FXP_STATUS, Size: 17, Number: 187654
< 2016-08-15 13:41:53.103 65,00,02,DD,06,00,00,00,00,00,00,00,00,00,00,00,00,
. 2016-08-15 13:41:53.103 Storing reserved response
. 2016-08-15 13:41:53.103 Waiting for another 4 bytes
. 2016-08-15 13:41:53.103 Looking for incoming data
. 2016-08-15 13:41:53.103 Looking for network events
. 2016-08-15 13:41:53.176 Detected network event
. 2016-08-15 13:41:53.176 Enumerating network events for socket 1224
. 2016-08-15 13:41:53.176 Enumerated 1 network events making 1 cumulative events for socket 1224
. 2016-08-15 13:41:53.176 Handling network read event on socket 1224 with error 0
. 2016-08-15 13:41:53.176 Selecting events 0 for socket 1224
. 2016-08-15 13:41:53.176 Incoming packet was garbled on decryption
. 2016-08-15 13:41:53.178 Connection was lost, asking what to do.
. 2016-08-15 13:41:53.179 Asking user:
. 2016-08-15 13:41:53.179 Incoming packet was garbled on decryption ()
* 2016-08-15 13:41:54.580 (ESshFatal) Incoming packet was garbled on decryption
* 2016-08-15 13:41:54.580 Copying files to remote side failed.
. 2016-08-15 13:41:57.604 --------------------------------------------------------------------------
. 2016-08-15 13:41:57.605 WinSCP Version 5.7.7 (Build 6257) (OS 6.1.7601 Service Pack 1 - Windows 7 Enterprise)
. 2016-08-15 13:41:57.605 Configuration: HKCU\Software\Martin Prikryl\WinSCP 2\
. 2016-08-15 13:41:57.605 Log level: Debug 2