Disable Next Button Until All Layers are visited

There are a couple of ways to do this, but my preferred way is to set a true/false variable on a slide. Let's call it V (for variable). The default value for V is "False."

On the slide you set a trigger that says "Change the state of the NEXT button to disabled when the timeline starts on this slide unless variable V is TRUE."

You set an additional trigger that says "Change the state of the NEXT button to normal when variable V changes if the state of V is TRUE."

Then you set the variable to change to True once the participant views all the information. If you are just having them go from one layer to the next, then I'd set a variable on the last layer that says "Adjust variable V to TRUE when timeline starts on this layer."

Sometimes I have a slide with several buttons, and a user has to click through each button to view the layer. You could have the variable change to true once the state of all of the buttons is "visited," but in this scenario I prefer a number variable. I would add a trigger to each slide layer "Add value 1 to V when the timeline starts on this layer,"

Let's say there are 5 layers you want them to see. You set your NEXT button triggers to "Change the state of the NEXT button to disabled when the timeline starts on this slide unless variable V less than or equal to 4."

and

"Change the state of the NEXT button to normal when variable V changes if V is greater than or equal to 5."

Does this help?