Your shopping cart is empty!
This is happening because you have Materials that are missing their texture maps. The software is asking you to locate the texture maps so the Materials can be loaded properly.
To find out which materials are missing their maps, look for the question mark. The software will put a question mark on any swatch that is missing a file.
To fix the problem, load the swatch into the material editor, click on the thumbnail showing the question mark and then find the missing map on your hard drive.
Alternatively, you can just delete all the swatches that have question marks on them.