<?php
class Brochure extends File{

   static $db = array (
      'Title' => 'Text',
      'Name_de' => 'Text',
      'Name_en' => 'Text',
      "ShowInSearch" => "Boolean"
   );

   static $belongs_many_many = array(
      'Pages' => 'Page'
   );
   
   static $singular_name = 'Brochure';
   static $plural_name = 'Brochures';
   
   static $defaults = array (
         'ShowInSearch' => 0
   );
   
   public function getCMSFields_forPopup()
   {   
      $filefield = new FileUploadField('Parent','PDF');
      $filefield->removeFolderSelection();
      $filefield->uploadFolder = 'brochures/';
      return new FieldSet(
         new TextField('Name_de'),
         new TextField('Name_en'),
         $filefield
      );
   }
   
   
   

   
}   
?>

class ReferencePage extends Page {
....

static $many_many = array (

      'Brochures' => 'Brochure',
   );

function getCMSFields() {
$fields = parent::getCMSFields();

...

// Adding Brochures      
          $brochurefilemanager = new ManyManyFileDataObjectManager(
            $this, // Controller
            'Brochures', // Source name
            'Brochure', // Source class
            'Parent', // File name on DataObject
            array(
               'Name' => 'Name'
               ), // Headings
            'getCMSFields_forPopup' // Detail fields (function name or FieldSet object)
            // Filter clause
            // Sort clause
            // Join clause
            );
            $brochurefilemanager->default_view = 'list';
            $brochurefilemanager->setAllowedFileTypes(array('pdf'));
            $brochurefilemanager->allowUploadFolderSelection = false;
            $brochurefilemanager->setUploadFolder('assets/brochures/');
            
         $fields->addFieldToTab("Root.Content.AttachedFiles",$brochurefilemanager);

....

}

But these DataObjects are no longer displayed within the backend or the frontend. I looked for them in my database. Tables are there and okay. Does anyone see the problem? Thank you for your help. SS-Version is 2.4.5 with latest version of the DataObject_Manager Module.

static $belongs_many_many = array(
'ReferencePages' => 'ReferencePage',
'VehiclePages' => 'VehiclePage'
);