Fatal error: Cannot call constructor in HtmlHelper.php (CakePHP)

I am using cakephp 2.1.1 for my app. I have a controller and I use the file cache in this controller. In the actions of the controller I call a SOAPService using the plugin NUSOAP.

I have two actions:

1. index

public function index() {
    $items = Cache::read('items', 'tenMinutes'); //tenMinutes is the configuration of cache

    if($items){
        $service = new Service();
        $items = $service->callService();
        Cache::write('items',$items,'tenMinutes');
    }

    $this->set('items',$items);
}

2. get_result

public function get_result() {
    $items = Cache::read('items','tenMinutes');

    if($items){

        //start block code filter items by params  
        ...
        //end

        $service = new Service();
        $result = $service->callService2($items);
        $this->set('result',$result);

    } else {

        //redirect index to load ítems
        $this->redirect(array('controller' =>'controllerName', 'action' => 'index'));
    }
}

The configuration of cache is:

Cache::config('tenMinutes', array(
        'engine' => 'File', //[required]
        'duration'=> '10 minutes', //[optional]
        'path' => CACHE, //[optional] use system tmp directory - remember to use absolute path
        'prefix' => 'cake_10_', //[optional]  prefix every cache file with this string
    ));

When I call index action and is the first time that cakephp writes in cache I have the following error:

Fatal error: Cannot call constructor in C:\wamp\www\myapp\lib\Cake\View\Helper\HtmlHelper.php on line 172

The second time I enter index and cache is already filled I click the button to take me to the second action (get_result), and this returns me the same error.

Can someone help me?

Thanks