Everything seemed to be configuring properly, but we can't get the hero slider or carousel to show up on the site. It all looks good when we're logged in as admin, but when we try to look at it through another (non logged-in) browser, we get an error window that says "It looks like a category has not been assigned for the Hero slides." Where the carousel should be, it says "The featured image carousel requires at least one post with a featured image." Of course, we have done this; it all looks fine viewing the pages with the admin login. I've tried looking at it on several computers on several browsers, and it looks the same.
I googled "It looks like a category has not been assigned for the Hero slides" which is one of the error messages on the pages. There are literally dozens of sites using this theme that are having the same problem. I tried getting help from Press75.com, and the tech's knowledge is terrible. He keeps saying it's a caching issue, and is more or less ignoring what I'm telling him.
Please, somebody help!