I am using the latest version of WinSCP 5.5.6 but I still have problem for the -passphrase switch to be recognized when using the open command. My scripting line is as follows and when I omit the passphrase switch and entering it manually everything works Ok. When I use the switch I get an error message "Unknown Switch". Documentation mentions that this is a feature of the latest version. Is 5.5.6 the latest version?
open sftp://secretboutique:firstname.lastname@example.org/ -privatekey="C:\Bitway.ppk" -passphrase="xxxxx"