Fix for framework / app / config / bootstrap / media.php

media.php

<?php
/**
 * Lithium: the most rad php framework
 *
 * @copyright     Copyright 2013, Union of RAD (http://union-of-rad.org)
 * @license       http://opensource.org/licenses/bsd-license.php The BSD License
 */

/**
 * The `Collection` class, which serves as the base class for some of Lithium's data objects
 * (`RecordSet` and `Document`) provides a way to manage data collections in a very flexible and
 * intuitive way, using closures and SPL interfaces. The `to()` method allows a `Collection` (or
 * subclass) to be converted to another format, such as an array. The `Collection` class also allows
 * other classes to be connected as handlers to convert `Collection` objects to other formats.
 *
 * The following connects the `Media` class as a format handler, which allows `Collection`s to be
 * exported to any format with a handler provided by `Media`, i.e. JSON. This enables things like
 * the following:
 * {{{
 * $posts = Post::find('all');
 * return $posts->to('json');
 * }}}
 */
use lithium\util\Collection;

Collection::formats('lithium\net\http\Media');

/**
 * This filter is a convenience method which allows you to automatically route requests for static
 * assets stored within active plugins. For example, given a JavaScript file `bar.js` inside the
 * `li3_foo` plugin installed in an application, requests to `http://app/path/li3_foo/js/bar.js`
 * will be routed to `/path/to/app/libraries/plugins/li3_foo/webroot/js/bar.js` on the filesystem.
 * In production, it is recommended that you disable this filter in favor of symlinking each
 * plugin's `webroot` directory into your main application's `webroot` directory, or adding routing
 * rules in your web server's configuration.
 */
use lithium\action\Dispatcher;
use lithium\action\Response;
use lithium\net\http\Media;

Dispatcher::applyFilter('_callable', function($self, $params, $chain) {
        $uri = ltrim($params['request']->url, '/');
        list($library, $asset) = explode('/', $uri, 2) + array("", "");

	if ($asset && ($path = Media::webroot($library)) && file_exists($file = "{$path}/{$asset}")) {
		return function() use ($file) {
			$info = pathinfo($file);
			$media = Media::type($info['extension']);
			$content = (array) $media['content'];

			return new Response(array(
				'headers' => array('Content-type' => reset($content)),
				'body' => file_get_contents($file)
			));
		};
	}
	return $chain->next($self, $params, $chain);
});

?>

The Request URL needs to have the first / trimmed before it can be exploded.