Difficulty blending layering landscape textures

I’m trying to make it so i can paint multiple textures onto my landscape (sand, dirt, pinefloor, etc.) and whenever i try to use the “layer blend” tool my scene loses all of its depth and the texture loads as black. I am trying to use a bump displacement map for all of my terrain textures too, so how can I integrate that? Is there another way that I can do this? Any help is immensely appreciated as i’ve been trying to salve this for days.

Here are some pictures of my landscape and materials: http://imgur.com/a/moc6I