Categories vs Concepts
After upgrading to SM17, I hit Alt+C. When I view the window, it appears that I have both the old structure (with category names) and a new one underneath (same structure, but with the light-bulb icon, meaning that the names are concepts). The information itself still appears to be in the old structure, although when I view the item with Ctrl+Shift+P, it refers to a concept group. Why are there two knowledge structures?
The confusion comes from the fact that all concepts need to have corresponding elements. This is why category upgrade produces a number of concepts that you can use, or delete. You will probably root all your new concepts in specific elements in the tree.