Triggers

There seem to be some extra triggers here so that may be throwing some wrenches in your project. Some of your layers for instance are set to play audio if the HTN box variable is true, not their own variable. I also don't think I understand why your layers are pausing toward the end, and then only after they've been clicked again to return to the base slide layer does the boolean variable they're assigned flip to true.

I think the main culprit is your trigger that Sets the state of the NEXT_BUTT2-"U" button to disabled. I can't find a place in the project where the variable it checks, ClickEachRevisited is changed to true, which means visiting the first slide will always trigger the button to disabled since the variable is always false. I added a trigger to the second slide's back button that changes the variable to true, and now the button is in the normal state when I revisit it.

That also eliminates the need for that Disabled trigger to check each of the BoxN variables. If the learner made it to the second slide, that's the proof they already viewed everything, right? So the one "is the learner revisiting this slide" variable should be enough.

Additionally, your Transparent layer that blocks the user from clicking the buttons is hiding the first time the slide viewed, after the base slide timeline ends, but when the learner revisits the first slide, the Resume Saved State of the base slide keeps the playhead at the end of the timeline (because that's where the learner left it, right?)

A consequence of that is that Storyline's "when the timeline ends on this slide" trigger doesn't re-fire, which means revisiting the slide doesn't re-hide your Transparent layer. It stays up the whole time, which is why I'm prevented from reclicking the buttons. I'm not sure if it's a deliberate design choice to both hide the cards upon revisiting as well as to prevent the learner from clicking them (then why am I revisiting the slide?) but I thought you should know.

TonyaMallard​: As AndrewBlemings-​ pointed out, the slide is more complicated than it needs to be. 

Here's my solution for your custom Next button: 

Delete this trigger.  

Instead, set the Initial state of the button to Disabled. 

When a user returns to the slide, the "Resumed saved state" setting will show the button in whatever state it was in when the user left the slide. 

By the way, the programming assumes that the user will click a card and then click it again on the associated layer to run additional triggers. However, I don't think that's intuitive. As a user, I wouldn't bother re-clicking a card after I flipped it. In fact, I'd want to see all of the risk factors at the same time. So I suggest you rethink the interaction.

One other note: when working with variables, it's a good idea to show the variable references on the slide during development. That let's you see whether or not the values change as expected. If the user doesn't need to see the values, you can hide or delete the textbox with the references before publishing.

Thanks so much, this solution worked.  The note regarding working with variables is a good idea too.