itch.io

That's weird. I've already asked itch.io about this. When I saw you comment, I purchased the game by myself and was able to download it without any issues. Can you please try again?

Already this game was purchased by many other  users and everyone, except you, was able to download it without problems

No, that's not true. I don't see any information about that in the admin panel. What's more, I proceeded with the purchase procedure, and I was able to download the content without any issues or warnings. So your information is false.