The bones sizes are limited?

I pressed ‘A’ in blender and scaled the skeletal mesh to (0.0001).
Applied the transform in blender and exported the mesh as fbx to import in ue4.
After importing the first error I got is the mesh is too small and not possible to create physics you have to create them manually. Ok I will do it.
The problem is why the root bone size is increased? while the mesh size is not increased.
This makes problems to calculate the sockets locations and rotations added to that bone because the bone is already bigger then the owners mesh.
Please suggest me a solution or fix this bug.