I'm not sure I can help that much since I run the original version of FH, but I'd actually just suggest you to do that as well instead of going through the hassle since it doesn't seem to work for you.
IF you use the very same download as others that got it to work, you are simply doing it wrong though I'd say.
Make sure you delete ALL of the old FH+ content that's installed on your computer before installing the newest version, and make sure you actually run the correct shortcut for the game, and not one that leads to an older version.
