Problem with CakePHP Excel

As the title says I am trying to implement CakePHP Excel, and with the 3 plugins tested so far:

• Cewi Excel
• dakota / CakeExcel
• maraya / CakePHPExcel

After installing them with Composer, and making all the configuration, when inserting this code (necessary) in the Appcontroler.php

public function initialize()
    {
            parent::initialize();
            $this->loadComponent('RequestHandler', [
                    'viewClassMap' => ['xlsx' => 'Cewi/Excel.Excel']
    ]);
        }

I missed the error var_export does not handle circular references.

I was researching the subject, but there is no clear information apparently about that error in CakePHP. Answers are appreciated from now.