When I tried to access to views/site/twitter.php, Yii::app()->twitter->isAuthorized was executed, and caused an error (CException).
Alias "pogostick.components.twitter.CPSTwitterApi" is invalid. Make sure it points to an existing PHP file.
I installed the pogostick Yii Extensions library under protected/extensions. There exists a file protected/extensions/pogostick/components/twitter/CPSTwitterApi.php
I was getting the same error, maybe this is an old post but it can help somebody that is facing the same problem.
I solve this by putting "ext." before "pogostick.components.twitter.CPSTwitterApi" like this: ext.pogostick.components.twitter.CPSTwitterApi in the main.php at config when you declare the class for the component. It should be like this: