I solved this issue. Just thought I'd let folks know who might be interested. I uninstalled my trial version, installed the purchased version, registered the product code (click on the options icon, then registration). Unfortunately, I
had to do this twice. The first time I did it, the program would begin to generate the collage and just before finalizing the picture, the canvas would go black. I reinstalled the product by going back to the microsoft online store and looking under
support, where you can find the products that you have purchased online along with their product codes (if you need them) .
Also, I called Microsoft technical support at 866-452-4755 (because the help person at the microsoft online store told me to do this), but they had no knowledge of this particular product and could only advise me to go to this forum and find the answer.
Since I had tried that route and had already posted my question, I thought it might be helpful to others if I also posted the solution.
Karen Muench