[CodeCeption] Functional Test Error.

Here is my Complete Functional test:

<?php
$I = new FunctionalTester($scenario);

$I->am('valid CN Admin user');
$I->wantTo('Login at CN Admin login page');

$I->haveAnCNAdminAccount([
    'username' => 'sachin',
    'email'    => 'sachin@example.com',
    'password' => 'sachin'
]);

$I->amOnPage('/cn/admin/login');
$I->see('LogIn!');
$I->fillField('Email:', 'sachin@example.com');
$I->fillField('Password:', 'sachin');
$I->seeCheckboxIsChecked('#remember');

$I->click('LogIn');

$I->canSeeCurrentUrlEquals('/cn/admin');
$I->canSee('sachin', 'nav');

And when I run this, I get the following error:

 [ErrorException] Codeception\Lib\InnerBrowser::getFormFromCrawler(): ID email already defined

Any Idea what does it mean. I searched Internet for this error. But Dint find proper solution for it.

P.S. Any suggestions on working with codeception and multiple route files? If I place my routes in a new file and require_once it in routes.php file then test fails because the page do not even load.