SecureBlackbox 16: The SSH / SFTP connection to JPMorgan (transmissions*.jpmorgan.com) fails. Why?

This is a known bug of their server software. It advertises support for keyboard-interactive authentication, but if the client uses this authentication mechanism the server returns error 11 and closes the connection.

Solution: Disable keyboard-interactive authentication using the AuthenticationTypes property of the SSH and SFTP client components when connecting to this server. (Keyboard-interactive authentication is enabled in the components by default.)