Hey there Abc,
I just want to make sure you understand what an inverted normal is, and what a bad edge is ... so, if you already know, please don't feel offended.
Understanding Inverted Normals
When a solid model, like a cube, is created, the polygons that make up this model are only one sided and face outwards. The inward side does not exist. If your view was put inside the solid cube looking out, you would not see the sides of the cube. You would see through them.
When one of the polygons on your model has an inverted normal, something has happened to switch the face inward instead of outward.
In this case, if your view was inside the model, then looking out, you would see that particular polygon with the inverted normal.
So, the solution is to choose that particular polygon, and "flip" the normal, as it is termed in 3DStudioMax and other programs.
The Bad Edge
In my experience, a bad edge has always been an edge where the vertices of the polygons don't actually connect.
A model where this occurs is often termed as a model that is not watertight. This description is useful, because if you imagine your model being filled with water, then technically the water would leak out of bad edges.
The solution here would be to select the vertices that should connect, and combine them together as one .. or "collapse" them as it is termed in 3DStudioMax
Hope this helps!
-Whystler