Thanks a bunch.
I couldnt import .Fbx files directly into MotionBuilder 2015 , it says it is an old fbx format , needs MotionBuilder 7 or 8 . but importing it into Maya first , then exporting it works . 
Thanks a bunch.
I couldnt import .Fbx files directly into MotionBuilder 2015 , it says it is an old fbx format , needs MotionBuilder 7 or 8 . but importing it into Maya first , then exporting it works .