Blank page with downloaded theme

I successfully downloaded a new theme and was using it, but then tried to download another one. But when I switched to the second theme, all I got was a blank page (www.taffystay.com). I went back to the Themes page, switched it to a couple of other ones, which all showed up fine. (Well, when I would “view site,” the page would just be blank. The images/text wouldn’t show up until I reloaded the page. But at least it worked.) But it is only with this theme, titled “Neat!” https://www.aamukaste.org/wpthemes/?cat=3 that doesn’t bring up ANYTHING on my page.

Has anyone encountered this, and how can I fix it? Thanks!