Blockbuster Theme Slider Issues

I have recently installed Blockbuster and while the slider worked perfectly when it was retrieving the original images (the ones that came with the theme), after I deleted those and replaced them with my own, it has stopped advancing.

The slider now only shows the first image and gives a “Not Found The requested URL /fp-next was not found on this server” error if you click on the slide arrows. I have run out of ideas on how to fix this. I only got this theme because I liked how clean it was and the slider. So if the slider doesn’t work, it’s no good to me.

Here’s my site: https://dirtygirlsministries.com (don’t let the name scare you… it’s clean).

Thanks for your help!
Crystal