Seeding -> Class not found

Hello,

i used CI 3 before and i liked it a lot and now i want to write a inhouse Solution for my Company. So i thought it would be nice to start  with the new seeding possibilites.

But somehow my seed class cant be found. I even tried the example from the docs and created the SimpleSeeder Class:

PHP Code:

<?php namespace App\Database\Seeds;

class SimpleSeeder extends \CodeIgniter\Database\Seeder
{
        public function run()
        {
                $data = [
                        'username' => 'darth',
                        'email'    => '[email protected]'
                ];

                // Using Query Builder
                $this->db->table('users')->insert($data);
        }
} 


The class is located in app/Database/Seeds/SimpleSeeder.php

And in the example Controller "Home.php" i called the seeder with:

PHP Code:

    public function index()
    {
                $seeder = \Config\Database::seeder();
                $seeder->call('SimpleSeeder');
        return view('welcome_message');
    } 


But every time i call the home Controller ill get the error Message that SimpleSeeder class could not be found. What am i missing here? And yes, i did the configuration for the Database in app/Config/Database.php