Import 3d character to UE4 "The bone size is too small to create Physics Asset from Skeletal Mesh"

[anonymous_user_7333e2c6]

I’m new to UE4 and have been learning the basic. I have a 3d character model rigged from Mixamo and I following this video tutorials

Skeleton Assets: Anim Retargeting Different Skeletons | 03 | v4.8 Tutorial Series | Unreal Engine

When I import 3d model to UE4 a messenger appear “Warning The bone size is too small to create Physics Asset from Skeletal Mesh . You will have to create physics asset manually”. Please help me. Thanks!
Model Download Link:
https://drive.google.com/file/d/0B8ibavbjYBOcWUVocDhOb2FsR2c/view?usp=sharing
Sorry my english is not good.