[TYPO3-mvc] Extbase and exceptions

[devweb]

Other Class is just :

class OtherClass {
  public function testException() {
    throw new \Exception('testException works?');
  }
}

In fact, this code is just an exemple, not my real code.
I can explain what i do in my real code. 
In an Extbase Controller i have got an function A with a throw exception when I dectect a bad situation.
In the same Extbase Controller, I use it in an Action and all works fine.
But I want to move the A function in an utility class because she has no place in my controller. So I copy/paste the code of my A function from the controller to the utility class. Since that, the exception no longer works.