Notice: A non well formed numeric value encountered on authentication Symfony 4 [closed]

Hello devs when I try to connect with my login form ( when I submit the form ) it doesn't work and gives me the following error:

Notice: A non well formed numeric value encountered

so thank you in advance for your answers

so I use the symfony 4 security component for authentication.

Here's the code:

Controller:

<?php

namespace App\Controller ;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;
use App\Entity\User ;

//Class pour authentification
use Symfony\Component\Security\Http\Authentication\AuthenticationUtils ;


class SecurityController extends AbstractController
{

  /**
  * @Route("/login" , name="login")
  */
  public function login(AuthenticationUtils $authentication)
  {
    $error = $authentication -> getLastAuthenticationError();

    $lastUsername = $authentication -> getLastUsername();

    return $this -> render('Authentification/login.html.twig' ,[

      'error'  => $error,
      'last_username' => $lastUsername,
      ]) ;

  }

}

Security.yaml :

security:
    encoders:
        App\Entity\User:
          algorithm: bcrypt
          cost :  14



    # https://symfony.com/doc/current/security.html#where-do-users-come-from-user-providers
    providers:
        # used to reload user from session & other features (e.g. switch_user)
        app_user_provider:
            entity:
                class: App\Entity\User
                property: username
    firewalls:
        dev:
            pattern: ^/(_(profiler|wdt)|css|images|js)/
            security: false
        main:
            anonymous: lazy

            form_login:

                remember_me: false

                check_path: /login


            logout :

                path: /logout

                target: /


            # activate different ways to authenticate
            # https://symfony.com/doc/current/security.html#firewalls-authentication

            # https://symfony.com/doc/current/security/impersonating_user.html
            # switch_user: true

    # Easy way to control access for large sections of your site
    # Note: Only the *first* access control that matches will be used
    access_control:

        - { path: ^/admin, roles: ROLE_ADMIN } 

and the login page :

{% extends 'baseConnection.html.twig' %}


{% block title %}Se Connecter{% endblock %}

{% block body %}
<div class="container">

  <br><br>

  <h3>Page de Connection de l'application CUMA le PROGRES</h3>

  <br><br>



  <p class="btn float-right color-br" onclick="window.history.back();">Retour</p>

  <br><br>

  {% if error %}

  <div class="alert alert-danger">

    {% if error %}

    {{ error.messageKey | trans(error.messagedata ,  'security') }}

    {% endif %}



  </div>

  {% endif %}

  <form  action="{{  path('login')}}" method="post">

    <div class="form-group">

      <label for="username">Nom d'utilisateur</label>

      <input type="text" id="username" name="_username" class="form-control" placeholder="Vôtre nom d'utilisateur est du style:    Prénom.Nom" value="{{ last_username }}">


    </div>

      <br>

      <div class="form-group">


          <label for="password">Mot de passe</label>

          <input type="password" id="password" name="_password" class="form-control" placeholder="Vôtre mot de passe ..... ( en cas d'oublie aller voir Fabien ABISUR )">


      </div>

      <br><br>

      <button type="submit" class="btn color-br">Se Connecter</button>

    </form>



</div>


{% endblock %}

thank you in advance for your help (^_^)