Various issues for example code is full of bugs:http://validator.w3.org/check?uri=http%3A%2F%2Fpsdtocodes.com%2Fedifice%2Ffull-width.html&charset=%28detect+automatically%29&doctype=Inline&group=0
Generally it feels out dated
Typography needs attention throughout as does hierarchy
Needs more to it in terms of features
Opt 1: In your download page click download & select ‘installable WordPress File Only’ & use this
Opt 2: Are you sure you have the WP theme and NOT a HTML file?
Opt 3: Are you using your own hosting and domain NOT WordPress.com
Opt 4: Unzip the theme folder and use ftp to install it