Models won't load

None of my models will load. No matter which one. I've tried different names, but I always get: "An Error Was Encountered

Unable to locate the model you have specified.” I'm at a loss.

/models/menu_model.php

PHP Code:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Menu_model extends CI_Model {
    
    function __construct() {
            parent::__construct();
    }
    
    function get_active_albums() {
        $query = $this->db->get_where('albums', array('is_active' = 1));
        
        return $query->result();
    }
} 


/controllers/welcome.php

PHP Code:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Welcome extends CI_Controller {
    
    public function __construct() {
        parent::__construct();
        $this->load->model('menu');
    }
    
    public function index() {
        $menu = $this->create_menu();
        $this->load->view('header');
        $this->load->view('welcome_message');
        $this->load->view('footer');
    }
    
    private function create_menu() {
        $data['query'] = $this->menu->get_active_albums();
        echo $data;
    }
}