Hide Next button until objects have been visited

Added triggers for each box "Change state of [box #] to Selected when user clicks."

Don't. All objects that have a selected state have built-in magic that changes their state to Selected when you click it, and back to Normal when you click again. The same goes for Hover, and the other built-in states. Creating your own triggers to do the same thing will only confuse SL, and a confused SL will often create some incredible, unbelievable, but seldom useful results.

I know when you use the wizard that "State of..." is one of the options for the When part of the trigger, but it doesn't work. There is nothing to make it happen. States do not initiate triggers. They are very useful in conditions. This is a known bug that doesn't work if there are more than five triggers on a slide.

The trigger you need is "Change state of Next to Normal When user clicks Box1 on condition state of Box2 is Selected, AND state of Box3 is Selected AND ... etc. "

You need one of these for each box.