Slight.error [2]: controller action not found

Request:
Controller:ErrorController
Action:indexAction

Error at [ line:82]: /lib/Slight/Http/Router.php

Included files [12]:
1./app/public/index.php
2./lib/Slight/bootstrap.php
3./lib/Slight/Kernel/App.php
4./lib/Slight/Kernel/ExceptionHandler.php
5./lib/Slight/Http/Router.php
6./app/Conf/routes.php
7./app/Controller/ErrorController.php
8./app/Controller/TemplateController.php
9./lib/Slight/Container/Controller.php
10./lib/Slight/Http/Session.php
11./lib/Slight/Http/RouterException.php
12./lib/Slight/Kernel/Logger.php