Visited state not working correctly

"Visited" is (and has always been) a built-in object state that is called automatically, without the need for triggers. Here is some info on built-in states.

AnriPesonen​: When you insert a Button, it will have the following states: Normal, Hover, Down, Visited, and Disabled. 

As Michael said, the Visited state works automatically, without the need for triggers. (The Hover and Down states also appear automatically. A trigger is needed to change a button to the Disabled state.)

When you insert shapes and other objects, they only have the Normal state. However, you can add built-in and/or custom states to them, as desired.

Even if an object doesn't have a trigger attached to it, if it has a Visited state, it will change to Visited when it is clicked. 

• Here's my post about built-in states: PRIMER: Take advantage of built-in states | Articulate - Community 
• As noted in that article, you shouldn't add triggers that duplicate the built-in changes that happen automatically. That might cause problems.

In your question, you said this: "Pictures have visited state with a star, and the state prohibits showing the layer attached to the picture."

• If the user can't re-click the picture-button, it sounds like the state with the star pasted in it is a Disabled state, not a Visited state. And there would be a trigger changing it to that state.
• If that star is in a Visited state, I'd guess that there's a 100%-transparent shape covering it. That prevents clicking an object below it. (Note: A user could still access the button with their keyboard, though.) If that is the case, there would be a trigger that changes the cover-shape from Hidden to Normal or that moves it on a motion path to cover the picture-button to prevent re-clicking the button. 

You also said: "Show layer trigger started working only after I removed all the visited state triggers form both base layer and the slide layers, which is a lot of work in this case."   [emphasis added]

• Does this mean there are buttons on the base and copies of the buttons on layers? That is bound to cause problems. Changing a button to Visited on one layer doesn't change a copy of the button to Visited on the base or on another layer. So you'd have to track what has and hasn't been clicked and adjust buttons states accordingly on each layer. 

Beyond that, troubleshooting is just guessing without seeing all the programming. Someone might be able to solve the issue if you upload the .story file. Here are the best practices for doing that:

• Only include slides that are related to the problem.
• Be sure objects, layers, motion paths, and variables have meaningful names.
• If there is proprietary content, replace or delete it. For example, replace proprietary text with “ipsum lorem” text.

I realized that the triggers came along when I copied images from a previous project. Removing the Visited states and the triggers seem to have solved the problem. I'll check for the transparent shape, thanks for the tip!