I am using WinSCP 6.6.2 RC Build 17374, looks like it fail to notify if the file exists, even when File setting overwrite setting turn off. I believe previous version explicitly bring overwriting confirmation window, which is no longer working. I am not sure, if this is a bug or some setting change in new version. I tried couple of things but it is not working and file just get overwrite without consent! I updated WinSCP 6.6.2 RC today and experience this issue.