Next button to appear after all layers have been viewed?

Hello! I am trying to do the same thing as Roland above. I have 9 layers on my slide, with hotspots to trigger the layers. I also have rectangle shapes built in on top of each hotspot with triggers to show the visited state when each hotspot/rectangle is clicked. I have the Next button set to disabled when the timeline starts on the slide, and I built a trigger to change the state of the Next button to normal when the state of all 9 rectangles is Visited. It is technically working--when you click the last LAYER, the Next button appears ON THE LAYER. But when I close out of the layer and go back to the BASE layer, the Next button is again disabled. What am I doing wrong??