multiple roots error on fbx import?

Hi, I’m not sure what’s happening here, hoping someone can clarify

as you can see, there’s only 1 root (and three geo objects with skin)… does anyone know whats happening (when I import the character, ue4 fails to import and says multiple roots are detected)? This is my second go at remaking this character rig… it imports into unity fine, i’m not really sure what the error is referring to

thanks for any help

found the problem if anyone else comes across it… in this case I had parented shoulder bones to controllers that were parented to the root. So even tho they were under a single root, all the bones were not within their own hierarchy … I imagine it like, if electricity were to flow from the root to all the bones, the charge would skip a bunch of bones (leg and spine) and go straight from the root to the shoulder controllers (so there were 2 “charge” paths, one from the root to the legs, and one from the root to the shoulders), which is what was causing the error

I solved it by created the bone/joint hierarchy first, then the controller hierarchy, and position/orientation constraining all the bones to their controllers instead of linking bones to controllers