Removing Sites::setupUrlPrefixes(). It was a bad idea to attempt this.

It slows down the app to a crawl.

A hackish solution is to modify CroogoRouter that inserts the
appropriate '/:site' route, and place it APP/Lib/CroogoRouter.php.
To use it instead Croogo's, add `App::uses('CroogoRouter', 'Lib');`
in APP/routes.php before doing anything.