Thanks - I had seen that - so the issue is that whilst a shell is not required for an SCP transfer, winSCP requires it because it tries to give a directory listing (which a command line transfer from linux does not) - which it can't do unless a shell is available?
Correct.
I don't suppose there is any way to configure winSCP to live with file transfer only, in situations where a shell is unavailable?
What's a point of using GUI SFTP client, if you cannot see the files you work with? How would that even work?