[TYPO3-english] fatal error when using t3lib_utility_Debug::debug()

[Muriel le Pair]

Hi,

I'm trying to migrate an old extension by rebuilding it with the extbase 
extension builder. But I'm lost nothing seems to work anymore like I'm 
just to.

first line of the class:
class CasesController extends 
\TYPO3\CMS\Extbase\Mvc\Controller\ActionController

But when I try to use the debugger or any other function I get a fatal 
error:

Fatal error: Class 'SF\SfCases\Controller\t3lib_utility_Debug

What am I missing?

--
kind regards,

Muriel le Pair