for some files when working with git, I suddenly get this message

What can I do? it seems to be related to visual studio code only!!

Might be related to "line endings". Maybe have a look at:
https://docs.github.com/en/get-started/getting-started-with-git/configuring-git-to-handle-line-endings
https://git-scm.com/book/en/v2/Customizing-Git-Git-Configuration#_core_autocrlf

Also, if the file is UTF-16, not plain ASCII or UTF-8, Git may treat it as a "binary" file 🤔