If you guys can't no longer use this and still want to calculate shadows on large maps i suggest you do this.
- Open the world editor
- Load your map
- Select all the doodads and destructibles of your map (Ctrl + A)
- Hit Cut (Ctrl + X), never replace your clipboard
- Now calculate the shadows with the standard shadow calculator provided by the World Editor, it shouldn't take long to render shadows because it does not calculate the shadows of your doodads, only the shape of your terrain.
- After the shadows have been calculated, hit Undo (Ctrl + Z), this should bring back all your doodads to your map.
Now enjoy your map having shadows while not sacrificing much of your time. You can do this thing everytime you update your terrain. I've been doing this trick for so long and this technique has been very effective.