There are three steps necessary in getting articles to display in your main featured slider:
1. You must make sure the value in Appearance >> Theme Options >> Front Page >> Featured Slider >> Featured Tag matches the name of the tag you want to use. To find the slug of the tag you want to use, go to Posts >> Tags and locate the tag in the list and look at the slug to the right of the tag name. Here is a screenshot to help you:
2. You must tag your articles with the tag you want to use. So, if you have chosen to use "featured" as your tag, you must tag your posts "featured". Here is a screenshot to help you:
3. You must assign featured images to the posts that you have tagged "featured". Here is a screenshot to help you.
If after doing these steps your featured slider still does not display anything at all, it is due to one of the following two reasons:
2) Another slider on the page is broken, which will also cause the Featured Slider to not work. Make sure your Latest Slider, Spotlight Slider, Trending Slider, Don't Miss slider, and Category Panels are all setup correctly on your home page (see Theme Options >> Front Page and Miscellaneous tabs to setup these sliders).
If, after making sure you try all of these steps, you are still unable to get the featured slider to work, please post a new ticket in our support center.