I've downloaded the theme spicy from the site. Unzipped everything and placed the folders spicy, spicy_blog, spicy_ecommerce and spicy_forum in the silverstripe\themes folder.
I changed the line in mysite\_config.php from SSViewer::set_theme('blackcandy'); to SSViewer::set_theme('spicy');. I get the above error. I've tried several other themes all with the same error but if I go back to blackcandy all is okay.