When you open file you downloaded from Vectorportal in Adobe Illustrator it is possible that some layers are not visible and therefore it may appear that part of the image is missing. All you need to do in this case is to check Layers palette and make all layers visible.
In Layers palette (Windows > Layers) an Eye icon indicates that layer is visible. In this case Layer 3 is visible and Layers 2 and 1 are not. Simply click on empty square in the first column to make layer visible.