How to make triggers pre-requisites to jump to next slide?

Yes.

• I'd create a T/F variable for each layer visited. Start with false.
• When the user gets to the layer set the variable from false to true with a trigger.
• On the base layer, change the state of next button to disabled when timeline starts on the condition that the layers are false.
• Add a trigger to change the next button to normal when the layer variables are all true.

If you don't use the next button, just do the conditional trigger on the object that navigates to the next slide.

Thank you Tom! I am going to try that out and report back.

A few additional tips:

• You can use custom states and evaluate the states of objects. 
• If you use variables, when you go to change the state of the next button (or object) there has to be a triggering event and then the conditions that the layer variables are all True.

Here's a quick recording of couple of ways to do this:

• state change
• variables

Thank you Tom. You have been a great help. I feel like I have set everything up correctly and sure I'm missing a minor detail. Will you please take a look at it and let me know what I did wrong?

You had a few issues so here's a recording where we walk through the basics with state changes. The previous video shows how to use variables. You need a separate variable for each layer.

Also, good habit to title things

Tom, you are amazing. Thank for this white-glove service. I am seriously floored by your support. Thank you!!