Actually, no. What's highlighted in that screenshot is just a part of the page. Where the blue line appears is where that section ends. The copyright notice thinks that where the blue line ends is where the bottom of the page is, so it appears just above the line. This also prevents me from clicking on any of the pages, because the area highlighted seems to be acting as a kind of layer. I don't really understand what's causing it, and I've tried removing that code, but it doesn't actually do anything beneficial.
To deal with the line, you should probably be focusing on the code of the line itself - whether you're trying to remove it or just change the settings. You might also want to see if there's a tag within the main page dictating where it ends, which could be wrong and clashing with the code for the line.
I'm not sure what you mean about the highlighted area preventing you from clicking on anything on the page. It could just be that you only need to remove one line of code (generally, I really advise against deleting or editing too many things at once. Deleting fewer lines or checking each line to see if it's what you'd like to change takes more time but also helps you identify and fix the problem). Was the layout already like that when you installed it? If so, maybe you should consider a different layout if this one is causing you so much trouble.