[TYPO3-mvc] "Sorry, the requested view was not found."

[Hendrik]

Hi,

I added a new action to the news extension and created a template in the same folder where the other templates are .
The action is called "lastAction", its placed in the "NewsController.php" and the Template is called "Last.html", placed under "Templates/News/"

I Think thats what the convention says, but I still get the error  "Sorry, the requested view was not found.".

I know its not a good practice to change an extension without using hooks etc. But thats not the point here, its more a general question: I have no idea how to debug this error. Convention over configuration is nice, but what can I do when it fails. Where can I see, where extbase watches for the template?