Backslash is incorrectly displayed as a crossed-out W.

I've attached a PNG image. The backslash is OK in a regular editor.
How can I fix this error?

Greetings from Cologne
Norbert

Is that a screenshot of WinSCP internal editor?
What encoding do you have set as default?
What encoding does the file actually have?
Can you share a sample file?

I'm in holiday. I will answer when I'm back.
Greetings
nobb