Help with Armature Not Moving Mesh?

Hi All,

New to blender
I am wondering why this armature is not moving the mesh after I parent them with automatic weights. Not working in Unity as well.

Also does anyone know what that black dotted line is that’s sticking out the back and how I can remove it?

Model is from here:
https://www.models-resource.com/playstation/megamanlegends2/model/20919/