Have a clean CodeIgniter framework installed.
Created file tests/acceptance/StartPageCept.php with following content

wantToTest('front page of my site'); $I->amOnPage('/'); $I->see('Welcome to CodeIgniter'); Running **php codecept.phar run acceptance --debug** and have this stack trace Couldn't test front page of my site (StartPageCept.php) Exception thrown Zend\Http\Exception\InvalidArgumentException: Invalid parameter type passed as Cookie Stack trace: #1 addCookie C:\Program Files\Zend\ZendServer\bin\PEAR\mink\vendor\fabpot\goutte\src\Goutte\Client.php:95 #2 createClient C:\Program Files\Zend\ZendServer\bin\PEAR\mink\vendor\fabpot\goutte\src\Goutte\Client.php:60 #3 doRequest C:\Program Files\Zend\ZendServer\bin\PEAR\Symfony\Component\BrowserKit\Client.php:265 #4 request C:\Program Files\Zend\ZendServer\bin\PEAR\mink\src\Behat\Mink\Driver\GoutteDriver.php:111 #5 visit C:\Program Files\Zend\ZendServer\bin\PEAR\mink\src\Behat\Mink\Session.php:127 #6 visit phar://C:/workspace/ten/codecept.phar/src/Codeception/Util/Mink.php:27