Can't connect using latest version of WinSCP to SCP server running on Windows 2008 R2 - OpenSSH

I've got a new build which I'm trying to get working with WinSCP, but I can't connect when using SCP. I'm using the latest version of WinSCP and on the server I'm using the latest version of OpenSSH.

I can connect with WinSCP when I use SFTP as the protocol.

I can connect from Terminal running on a MacBook or Ubuntu client.

However, I get the following when trying to connect using SCP:
Searching for host...
Connecting to host...
Authenticating...
Using username "administrator"
Authenticating with pre-entered password
Authenticated.
Starting the session...

HANGS here...
After 15 seconds...

Host is not communicating for more than 15 seconds.
Still waiting...

Note: If the problem repeats, try turning off 'Optimize connection buffer size'.
Warning: Aborting this operation will close connection!

Error skipping startup message. You sell is probably incompatible with the application (BASH is recommended).

My WinSCP client connects to other SCP servers just fine. I'm having problems with the one I have installed on my Windows 2008 R2 server.

OpenSSH Log file:
3060 22:02:07:350 Server listening on :: port 22.
3060 22:02:07:350 Server listening on 0.0.0.0 port 22.
3768 22:02:13:200 Accepted password for administrator from 192.168.20.5 port 50101 ssh2
3240 22:02:20:235 Accepted password for administrator from 192.168.20.5 port 50100 ssh2
3240 22:02:45:507 Received disconnect from 192.168.20.5 port 50100:11: disconnected by user
3240 22:02:45:507 Disconnected from user administrator 192.168.20.5 port 50100

I've tried different variations of SCP/Shell under Advanced Site Settings
Shell: Default, Return Code Variable: Autodetect
ALL FAIL...

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

. 2017-12-28 11:40:36.690 --------------------------------------------------------------------------
. 2017-12-28 11:40:36.690 WinSCP Version 5.11.3 (Build 7995) (OS 6.1.7601 Service Pack 1 - Windows Server 2008 R2 Datacenter)
. 2017-12-28 11:40:36.690 Configuration: HKCU\Software\Martin Prikryl\WinSCP 2\
. 2017-12-28 11:40:36.690 Log level: Debug 1
. 2017-12-28 11:40:36.690 Local account: WIN-R3DNIL9HPI9\Administrator
. 2017-12-28 11:40:36.690 Working directory: C:\Program Files (x86)\WinSCP
. 2017-12-28 11:40:36.690 Process ID: 4940. 2017-12-28 11:40:36.894 Session upkeep
. 2017-12-28 11:40:37.372 Session upkeep
. 2017-12-28 11:40:37.912 Session upkeep
. 2017-12-28 11:40:38.413 Session upkeep
. 2017-12-28 11:40:38.913 Session upkeep
. 2017-12-28 11:40:39.413 Session upkeep
. 2017-12-28 11:40:39.913 Session upkeep
. 2017-12-28 11:40:40.463 Session upkeep
. 2017-12-28 11:40:40.963 Session upkeep
. 2017-12-28 11:40:41.463 Session upkeep
. 2017-12-28 11:40:41.963 Session upkeep
. 2017-12-28 11:40:42.463 Session upkeep
. 2017-12-28 11:40:42.964 Session upkeep
. 2017-12-28 11:40:43.464 Session upkeep
. 2017-12-28 11:40:43.964 Session upkeep
. 2017-12-28 11:40:44.514 Session upkeep
. 2017-12-28 11:40:45.284 Session upkeep
. 2017-12-28 11:40:45.800 Session upkeep
. 2017-12-28 11:40:46.300 Session upkeep
. 2017-12-28 11:40:46.850 Session upkeep
. 2017-12-28 11:40:47.350 Session upkeep
. 2017-12-28 11:40:47.850 Session upkeep
. 2017-12-28 11:40:48.351 Session upkeep
. 2017-12-28 11:40:48.851 Session upkeep
. 2017-12-28 11:40:49.351 Session upkeep
. 2017-12-28 11:40:49.901 Session upkeep
. 2017-12-28 11:40:50.401 Session upkeep
. 2017-12-28 11:40:50.901 Session upkeep
. 2017-12-28 11:40:51.401 Session upkeep
. 2017-12-28 11:40:51.901 Session upkeep
. 2017-12-28 11:40:52.401 Session upkeep
. 2017-12-28 11:40:52.909 Session upkeep
. 2017-12-28 11:40:53.399 Session upkeep
. 2017-12-28 11:40:53.913 Session upkeep
. 2017-12-28 11:40:54.414 Session upkeep
. 2017-12-28 11:40:54.927 Session upkeep
. 2017-12-28 11:40:55.505 Session upkeep
. 2017-12-28 11:40:55.941 Session upkeep
. 2017-12-28 11:40:56.441 Session upkeep
. 2017-12-28 11:40:56.955 Session upkeep
. 2017-12-28 11:40:57.455 Session upkeep
. 2017-12-28 11:40:57.969 Session upkeep
. 2017-12-28 11:40:58.470 Session upkeep
. 2017-12-28 11:40:58.984 Session upkeep
. 2017-12-28 11:40:59.484 Session upkeep
. 2017-12-28 11:40:59.998 Session upkeep
. 2017-12-28 11:41:00.501 Session upkeep
. 2017-12-28 11:41:01.012 Session upkeep
. 2017-12-28 11:41:01.513 Session upkeep
. 2017-12-28 11:41:02.026 Session upkeep
. 2017-12-28 11:41:02.526 Session upkeep
. 2017-12-28 11:41:03.040 Session upkeep
. 2017-12-28 11:41:03.540 Session upkeep
. 2017-12-28 11:41:04.054 Session upkeep
. 2017-12-28 11:41:04.554 Session upkeep
. 2017-12-28 11:41:05.068 Session upkeep
. 2017-12-28 11:41:05.568 Session upkeep
5 Looking up host "localhost" for SSH connection
. 2017-12-28 11:40:36.706 Connecting to ::1 port 22
. 2017-12-28 11:40:36.706 We claim version: SSH-2.0-WinSCP_release_5.11.3
. 2017-12-28 11:40:36.720 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:36.720 Detected network event
. 2017-12-28 11:40:36.761 Detected network event
. 2017-12-28 11:40:36.761 Server version: SSH-2.0-OpenSSH_7.6
. 2017-12-28 11:40:36.761 Using SSH protocol version 2
. 2017-12-28 11:40:36.761 Have a known host key of type ssh-ed25519
. 2017-12-28 11:40:36.761 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:36.762 Detected network event
. 2017-12-28 11:40:36.762 Doing ECDH key exchange with curve Curve25519 and hash SHA-256
. 2017-12-28 11:40:36.791 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:36.791 Detected network event
. 2017-12-28 11:40:37.239 Server also has ecdsa-sha2-nistp256/ssh-rsa host keys, but we don't know any of them
. 2017-12-28 11:40:37.241 Host key fingerprint is:
. 2017-12-28 11:40:37.241 ssh-ed25519 256 aa:0d:6f:ff:1c:ac:9b:e8:98:82:70:80:54:39:f6:f4
. 2017-12-28 11:40:37.241 Verifying host key ssh-ed25519 0xbd0357d700183876 5c5afb88a5598552 236afdf3c2e743f6 e89240f33470a3a,0x4daac08e332c4bc5 49775ee573c5e69d f609d9132225cb08 5802d93d65bfcd56 with fingerprint ssh-ed25519 256 aa:0d:6f:ff:1c:ac:9b:e8:98:82:70:80:54:39:f6:f4
. 2017-12-28 11:40:37.245 Host key matches cached key
. 2017-12-28 11:40:37.246 Initialised AES-256 SDCTR client->server encryption
. 2017-12-28 11:40:37.246 Initialised HMAC-SHA-256 client->server MAC algorithm
. 2017-12-28 11:40:37.246 Initialised AES-256 SDCTR server->client encryption
. 2017-12-28 11:40:37.246 Initialised HMAC-SHA-256 server->client MAC algorithm
. 2017-12-28 11:40:37.246 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.246 Detected network event
! 2017-12-28 11:40:37.246 Using username "administrator".
. 2017-12-28 11:40:37.257 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.257 Detected network event
. 2017-12-28 11:40:37.258 Server offered these authentication methods: publickey,password,keyboard-interactive
. 2017-12-28 11:40:37.258 Attempting keyboard-interactive authentication
. 2017-12-28 11:40:37.258 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.258 Detected network event
. 2017-12-28 11:40:37.258 Server refused keyboard-interactive authentication
. 2017-12-28 11:40:37.258 Server offered these authentication methods: publickey,password,keyboard-interactive
. 2017-12-28 11:40:37.258 Prompt (password, "SSH password", <no instructions>, "&Password: ")
. 2017-12-28 11:40:37.258 Using stored password.
. 2017-12-28 11:40:37.268 Sent password
. 2017-12-28 11:40:37.268 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.268 Detected network event
. 2017-12-28 11:40:37.268 Access granted
. 2017-12-28 11:40:37.268 Opening session as main channel
. 2017-12-28 11:40:37.268 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.269 Detected network event
. 2017-12-28 11:40:37.269 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.269 Detected network event
. 2017-12-28 11:40:37.269 Opened main channel
. 2017-12-28 11:40:37.269 Waiting for the server to continue with the initialization
. 2017-12-28 11:40:37.316 Detected network event
. 2017-12-28 11:40:37.316 Started a shell/command
. 2017-12-28 11:40:37.340 --------------------------------------------------------------------------
. 2017-12-28 11:40:37.340 Using SCP protocol.
. 2017-12-28 11:40:37.340 Doing startup conversation with host.
. 2017-12-28 11:40:37.340 Session upkeep
. 2017-12-28 11:40:37.340 Detected network event
. 2017-12-28 11:40:37.340 Received 36 bytes (0)
. 2017-12-28 11:40:37.340 Received 2 bytes (0)
. 2017-12-28 11:40:37.340 Received 63 bytes (0)
. 2017-12-28 11:40:37.340 Received 2 bytes (0)
. 2017-12-28 11:40:37.340 Received 2 bytes (0)
. 2017-12-28 11:40:37.340 Received 53 bytes (0)
. 2017-12-28 11:40:37.362 Skipping host startup message (if any).
> 2017-12-28 11:40:37.362 echo "WinSCP: this is end-of-file:0"
. 2017-12-28 11:40:37.362 Sent 37 bytes
. 2017-12-28 11:40:37.362 There are 0 bytes remaining in the send buffer
. 2017-12-28 11:40:37.362 Read 38 bytes (120 pending)
< 2017-12-28 11:40:37.362 Microsoft Windows [Version 6.1.7601]

. 2017-12-28 11:40:37.362 Read 65 bytes (55 pending)
< 2017-12-28 11:40:37.362 Copyright (c) 2009 Microsoft Corporation. All rights reserved.

. 2017-12-28 11:40:37.362 Read 2 bytes (53 pending)
< 2017-12-28 11:40:37.362

. 2017-12-28 11:40:37.362 Read 53 bytes (0 pending)
. 2017-12-28 11:40:37.362 Waiting for another 1 bytes
. 2017-12-28 11:40:37.363 Detected network event
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 1 bytes (0)
. 2017-12-28 11:40:37.363 Received 37 bytes (0)
. 2017-12-28 11:40:37.363 Read 1 bytes (73 pending)
. 2017-12-28 11:40:37.363 Read 36 bytes (37 pending)
< 2017-12-28 11:40:37.363 administrator@WIN-R3DNIL9HPI9 C:\Users\Administrator>echo "WinSCP: this is end-of-file:0"
. 2017-12-28 11:40:37.363 Read 37 bytes (0 pending)
< 2017-12-28 11:40:37.363 echo "WinSCP: this is end-of-file:0"
. 2017-12-28 11:40:37.363 Waiting for another 1 bytes
. 2017-12-28 11:40:37.363 Detected network event
. 2017-12-28 11:40:37.363 Received 33 bytes (0)
. 2017-12-28 11:40:37.363 Read 1 bytes (32 pending)
. 2017-12-28 11:40:37.363 Read 32 bytes (0 pending)
< 2017-12-28 11:40:37.363 "WinSCP: this is end-of-file:0"

. 2017-12-28 11:40:37.363 Waiting for another 1 bytes
. 2017-12-28 11:40:37.364 Detected network event
. 2017-12-28 11:40:37.364 Received 2 bytes (0)
. 2017-12-28 11:40:37.364 Received 53 bytes (0)
. 2017-12-28 11:40:37.364 Read 1 bytes (54 pending)
. 2017-12-28 11:40:37.364 Read 1 bytes (53 pending)
< 2017-12-28 11:40:37.364

. 2017-12-28 11:40:37.364 Read 53 bytes (0 pending)
. 2017-12-28 11:40:37.364 Waiting for another 1 bytes
. 2017-12-28 11:40:52.885 Waiting for data timed out, asking user what to do.
. 2017-12-28 11:40:52.885 Asking user:
. 2017-12-28 11:40:52.885 **Host is not communicating for 15 seconds.
. 2017-12-28 11:40:52.885
. 2017-12-28 11:40:52.885 Wait for another 15 seconds?** ()
. 2017-12-28 11:40:52.885 Session upkeep
. 2017-12-28 11:40:53.885 Session upkeep
. 2017-12-28 11:40:54.885 Session upkeep
. 2017-12-28 11:40:55.506 Attempt to close connection due to fatal exception:
* 2017-12-28 11:40:55.506 **Terminated by user.**
. 2017-12-28 11:40:55.506 Closing connection.
. 2017-12-28 11:40:55.506 Sending special code: 12
. 2017-12-28 11:40:55.506 Sent EOF message
* 2017-12-28 11:40:55.519 (EFatal) **Terminated by user.**
* 2017-12-28 11:40:55.519 Error skipping startup message. Your shell is probably incompatible with the application (BASH is recommended).

That's not a complete log file.
Anyway, why are you using SCP? Use SFTP.