render_theming_css tag does not work on windows
The approach of joining url path components with os.path.join() does not work properly on win as the defaulet separator is '\' and not '/' as expected in a url.
I think it would be safer to use the join() method of string:
def render_theming_css(): """ Template tag that renders the needed css files for the theming app. """ css = getattr(settings, 'ADMIN_TOOLS_THEMING_CSS', False) if css: css = '/'.join([get_media_url(), css]) else: css = '/'.join([get_media_url(), 'admin_tools', 'css', 'theming.css']) return '<link rel="stylesheet" type="text/css" media="screen" href="%s" />'