Please upgrade to the latest version of WinSCP.
Also, I'm able to connect fine to this FTP server using the FileZilla GUI by selecting Encryption: "Require explicit FTP over TLS". Thanks!
Executing:
open ftps://user:password@FTPServerIP/ -explicitssl -certificate="[Certificate]"
Results in:
Unknown switch 'explicitssl'
I'm running version 4.1.9. The 'implicit' switch yielded the same error. Any suggestions? Thanks.