I began a new file with a blank artboard that had no grid lines. Next, I created a second artboard, used the Grid and Axis Manager to set up the grid I needed, and added some lines to that artboard. My next step was to create a copy of the second artboard, which appeared correctly with the grid I had established and the lines I had drawn. I renamed the second and third arboards, and then decided that I wasn't going to use the first artboard, which was still blank and without grid lines.
When I deleted that first artboard, a grid suddenly appeared over both of the remaining artboards AND th