This is probably the same issue as UE-38935. This crash happens when importing skeletal mesh that has no material.
UE-38935 Crash with FBX Import as Skeletal Mesh Unreal Engine Issues and Bug Tracker (UE-38935)
It is already fixed and target fix version is 4.14.1. I tested the fix with the fbx files in this topic, and they no longer crash on import.