Cannot find an overload for "SynchronizeDirectories" and the argument count: "3".

Try to synchronize remote SFTP directory with the local UNC path.
Getting the follow error:

Cannot find an overload for "SynchronizeDirectories" and the argument count: "3".
Not sure where to look.

The Session.SynchronizeDirectories indeed needs at least 4 arguments:
https://winscp.net/eng/docs/library_session_synchronizedirectories