Symfony 3.4 - I have issue using knp-paginator-bundle - symfony-3.4

Question

I have the following controller
/**
*
* #Route("/searchname" , name="search_student_name")
*
*/
public function SearchStudentName(Request $request, SessionInterface $sessionName)
{
$params = $request->request->all();
$SName = $params['txtSearchName'];
if (isset($SName)){
$sessionName->set('SName', $SName);
}
$em = $this->getDoctrine()->getManager();
$query = $em->createQuery("SELECT s FROM AppBundle:Student s WHERE s.name LIKE :Name ORDER BY s.name");
$query->setParameter('Name', '%'.$sessionName->get('SName').'%');
$students = $query->getArrayResult();
$paginator = $this->get('knp_paginator');
$result = $paginator->paginate(
$students,
$request->query->get('page', 1)/*page number*/,
50/*limit per page*/
);
return $this->render('student/index.html.twig', array(
'students' => $result,
));
}
The first page was displayed correctly.
But When I am trying to go to other page
app_dev.php/student/searchname?page=2
I have the following error:
NotFoundHttpException
HTTP 404 Not Found
AppBundle\Entity\Student object not found by the #ParamConverter annotation.
I have the indexAction which works fine for any page:
the only difference is $students = $em->getRepository('AppBundle:Student')->findAll();
and the use of session to save the name
/**
* Lists all student entities.
*
* #Route("/", name="student_index")
* #Method("GET")
*/
public function indexAction(Request $request)
{
$em = $this->getDoctrine()->getManager();
$students = $em->getRepository('AppBundle:Student')->findAll();
/**
* #var $paginator \Knp\Component\Pager\Paginator
*/
$paginator = $this->get('knp_paginator');
$result = $paginator->paginate(
$students,
$request->query->get('page', 1)/*page number*/,
50/*limit per page*/
);
return $this->render('student/index.html.twig', array(
'students' => $result,
));
}
Can someone help me how to solve this issue?
Session value

Answer 1

Maybe $sessionName->get('SName') is empty or null ?, you can try put a default value for the session like this:
$sessionName->get('SName', 'something default');