Sucuri security check: Unable to scan the page. 404 Not Found

Hi, I'm trying out this theme and assembling other components with this theme. When using the Sucuri site check it shows just one notification/error: Site Issue Detected. Unable to scan the page. 404 Not Found https://www.petalrocks.com/wp-content/themes/catch-revolutionassets/js/html5.min.js?ver=3.7.3   Can you explain what is the file that Sucuri is trying to scan? Many thanks.