Next button not appearing after slide visits

Thanks for setting this up for testing. That makes it a lot quicker and easier than having to slog through the whole project.

Two problems: The first is that no matter the state of the hex shapes, the first trigger sets Next to disabled when it starts. The "When state of ..." has always been shaky, but it only works at the moment the state changes, so you are having trouble with it. You can make it work by adding conditions to it:

That brings what to me is a new problem. The button changes as soon as the last hex is clicked, and could be clicked as the slide is fading.  I would much prefer to use this trigger:

in conjunction with the one above. Not only is it a better time to change the state, but is a much more reliable function than "When state is ...". That has been improved over the years, but I have had enough bad experiences with it that I don't trust it. YMMV

The other thing you should know is that there are problems with these two triggers, and the ones like them:

First, when a "Jump to ..."trigger is encountered, it immediately jumps, and cuts off the execution of all the triggers that follow it. Your triggers to set the state to visited never get executed. Which is fortunate for you, because the built-in states (like Visited) all have built-in superpowers. An object with a visited state will automatically change to Visited if it is clicked. Writing triggers that duplicate that function can cause serious and unpredictable conflicts. So delete the Set state triggers, and in the future put the Jump trigger at the very bottom of the list.