Hi!
I got some help from David Deraedt - Creative Cloud Consultant - Adobe Systems France. Here is what he suggested;
"Ok, so you should first open it in notepad and go to the encoding settings and make sure it’s set to UTF8 and then save it."
So I did so and noticed that my json file was in ANSI (charset). Saved the file with UTF-8. And now everything is ok.
So thank you to all of you who gave me a helping hand!
BR
/Bengt