I suppose there could be two reasons for this...
I personally do not suggest getting FerealHeart+ at all, due to glitches and what not that can occur.
Either way, if you really want to fix the mod, here is a link. (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=13593.0)
The blackness could also be caused by a glitch with ogre.
This is if the adverts for ogre do not show up when you launch the game.
If you're running OpenGL, switch to DirectX9.
If you're running DirectX9, try OpenGL.
Here's a video that shows how to do it.
http://www.youtube.com/watch?v=RuvsHxCixck (http://www.youtube.com/watch?v=RuvsHxCixck)