Correctifs

Controller/Admin/AbstractCrudController.php

 use Lc\SovBundle\Field\CollectionField;
 use Lc\SovBundle\Field\GalleryManagerField;
 use Lc\SovBundle\Form\Type\Crud\PositionType;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\Form\Extension\Core\Type\CollectionType;
 use Symfony\Component\Form\Extension\Core\Type\TextType;
 use Symfony\Component\HttpFoundation\RequestStack;

Resources/views/adminlte/dashboard.html.twig

 {% block content_title 'SovBundle' %}
 
 {% block main %}
-    Bien sur votre tableau de bord
-    Salut !!!
+    Tableau de bord par défaut.
 {% endblock %}