What version of WinSCP are you using?
What protocol?
Are you editing the file in an Internal editor of WinSCP or external editor?
What encoding does the file have? ANSI (874) or UTF-8?
If you are using an Internal editor, did you try changing the encoding? See https://winscp.net/eng/docs/ui_editor
What protocol?
Are you editing the file in an Internal editor of WinSCP or external editor?
What encoding does the file have? ANSI (874) or UTF-8?
If you are using an Internal editor, did you try changing the encoding? See https://winscp.net/eng/docs/ui_editor