Call to undefined method CI_Controller::Controller()

[eluser]yuro[/eluser]
Hello,

I uploaded my CodeIgniter Version to 3.0, because the old version had shown a Error on google.com and now come the next problem:

Error: Call to undefined method CI_Controller::Controller()in /.../frontendcontroler.php on line 20

Thats the code:

Code:

function __construct()
  {
parent::Controller(); //Error
  ....

Where's the problem? I'm using CI3.0