Symfony - Sonata "Admin service "app.admin.post" not found in admin pool."

I get the following error while trying to access the dashboard.

An exception has been thrown during the rendering of a template ("Admin service "app.admin.post" not found in admin pool.")

I use this tutorial ""5.3.2. Using the config.yml"" and I have no idea why I have this error https://symfony.com/doc/current/bundles/SonataAdminBundle/reference/dashboard.html

sonata_admin:
templates:
    dashboard: SonataAdminBundle:Core:dashboard.html.twig
dashboard:
    groups:
        app.admin.group.content:
            label: app.admin.group.content
            label_catalogue: AppBundle
            items:
                - app.admin.post

        app.admin.group.blog:
            items: ~
            item_adds:
                - sonata.admin.page
            roles: [ ROLE_ONE, ROLE_TWO ]

        app.admin.group.misc: ~