does this person have their plan view background color set to black? Or did they ever even briefly have it set to black and change it to white?
Check the Grids and Backgrounds dialog in the plan view. And then check it again while in the layout view. If the while in the layout view the grid background shows black, then this is part of the problem. I had a similar problem with a template file that had a yellow background. i changed it to white but when I go to my layouts, all items that use the -1 recognize the background as being yellow. In your case, I would guess it is recognizing black. It could be that an AutoCAD drawing was open and the user elected to change the archicad background to match the typical black autocad background and may have stuck the work environment.
Unfortunately, I have no solution yet. In fact, that is why I am here looking for one myself.