Slideshow and thumbnails not generating on Photoria theme

I’ve recently installed the Photoria theme and I’m having trouble getting the thumbnails and slideshow images to generate. The images appear just fine in my posts, but they don’t show up at all on the homepage. I tried replacing the timthumb.php in my cPanel, but this only appears to have made things worse. Can someone please take a look at https://www.johntographer.com and send me in the right direction?

Thank you for your time and help!