Hey, i just wrote a whole book of things i tried, and the solution is dumb as f***.
First i wanna say really thank you for your help, i didnt expect any kind of help. This was really cool.
In Case this happens to anyone else too i wanna tell you the solution.
i‘m a mac user since 2012. and because your tool is the only one avaiable which has this kind of feature, im forced to use my girlfriends notebook. but i surfed itch over my mac. downloaded it over the mac and send it to the windows notebook via an usb drive. i cant explain why this makes any difference (fat32 format usb drive) but this time i downloaded it directly to the notebook and it was just working fine... doesnt even make sense, but hey i can finally use it :D