When using the fetch method to pull down the css or js files it doesn't prefix the path.
For example if I have an app at:
http://domain.com/HelloWorld
and the webroot is here:
domain.com/html/HelloWorld/App/webroot/
So instead of getting:
/HelloWorld/css/shrink_fd92fc8fcce629a200415826e4b96d9c.css
you get:
/css/shrink_fd92fc8fcce629a200415826e4b96d9c.css