I have a model that works fine in unity but when I add a bone structure to it in maya and reimport it into unity it dissappears?
Is the mesh invisible as soon as you import into Unity or when you run the game? If the mesh has vanished on import, then try zooming in to see if there is a scaling problem. If the mesh disappears when you run the game, then try putting it inside a parent object and running again. Generally, an animation on a root object will run in world space rather than the object’s local space, so the mesh may appear miles away from the object’s anchor point.
Thanks, it was a zooming issue 