ah_post_send (#0), code is 404 (want 401)

Trying to do a batch transfer. Getting this error. What does it mean? I can connect manually fine.

. 2018-09-24 11:34:24.359 Using TLSv1.2, cipher TLSv1/SSLv3: ECDHE-RSA-AES256-SHA384, 1024 bit RSA
. 2018-09-24 11:34:24.359 Request sent; retry is 0.
. 2018-09-24 11:34:24.382 [status-line] < HTTP/1.1 404 Not Found
. 2018-09-24 11:34:24.382 Header Name: [content-length], Value: [400]
. 2018-09-24 11:34:24.382 Header Name: [date], Value: [Mon, 24 Sep 2018 15:34:24 GMT]
. 2018-09-24 11:34:24.382 Header Name: [server], Value: [Apache]
. 2018-09-24 11:34:24.382 End of headers.
. 2018-09-24 11:34:24.382 ah_post_send (#0), code is 404 (want 401), WWW-Authenticate is (none)
. 2018-09-24 11:34:24.382 Request ends, status 404 class 4xx, error line:
. 2018-09-24 11:34:24.382 404 Not Found
. 2018-09-24 11:34:24.382 Request ends.
. 2018-09-24 11:34:24.383 sess: Destroying session.
. 2018-09-24 11:34:24.383 sess: Closing connection.
. 2018-09-24 11:34:24.383 sess: Connection closed.

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