[IntoRain]

What is the specific error?

That spire theme is a year old, I don't know if the styling changed in one year, if it did you will need to make some changes.

Basically, the way it works now, the HTML to structure the page is in .tpl files. I advise to check out header.tpl and template.tpl. The footer, sidebar, menu, etc. is added in template.tpl.

The code you downloaded must come with these .tpl files as well as the .css to style the page. In your admin panel, you can create the theme by copying the .css, template and header and once the new folder is created add any extra files the new theme needs. Or maybe going to your themes folder, picking a theme (main for example) and trying to change the files there to the new ones you downloaded will be easier