I have apachesolr index search with Search API attachments. In the results I get a link to the file but I would like to get a link to the parent node. I tried in the view but there is no such field with relationship to file usage.
I wrote the following in a module to override the field fid in the view but it returns an error

    function hook_preprocess_views_view_field(&$variables) {
    $view = $variables['view'];
    $field = $variables['field'];
   		if ($view->storage->id() == 'saa' &&
  		$view->current_display == 'page_1' &&
  		$field->field == 'fid') {
  			$fid =  $variables['output']; 
  			$file = \Drupal\file\Entity\File::load($fid);
 			$file_usage = \Drupal::service('file.usage')->listUsage($file);
       		$variables['results'] = $file_usage;
    	}
	}

It returns
>The website encountered an unexpected error. Please try again later.
TypeError: Argument 1 passed to Drupal\file\FileUsage\DatabaseFileUsageBackend::listUsage() must implement interface Drupal\file\FileInterface, null given, called in /home/rebecca/public_html/new5/modules/pdf_app/pdf_app.module on line 262 in Drupal\file\FileUsage\DatabaseFileUsageBackend->listUsage() (line 123 of core/modules/file/src/FileUsage/DatabaseFileUsageBackend.php).