How to fix FBX Smoothing Groups Error?

Whenever I try to import an FBX mesh with a skeleton to UE4, there is this warning stating that there is no group smoothing in the FBX scene and to please enable it???

I am closing this question as a Duplicate of https://answers.unrealengine.com/questions/177807/how-to-fix-fbx-smoothing-groups-error-1.html