Bug in VOSIO Wordpress Theme

I am trying to install the VOSIO Wordpress Theme but i keep getting the error that there is not CSS file. I extracted and saw a CSS file. Is it a bug or am i doing something wrong.
i sent a message to ThemeWisdom, the developer but have not heard back from them

Is it definitely the WP version not the HTML version?

If so, the error occurs when the file you are trying to upload into WordPress is not a valid theme file. Please go back to your downloads page and download the theme again, making sure to select “Installable WordPress file only.”

If you don’t see this option, then you may have purchased an item which is not compatible with WordPress. I would suggest contacting the author of the item you purchased to see if they offer a WordPress version and can help you exchange it.

Hope this helps!