EntityMalformedException on creating/editing feeds importer

I just installed feeds and wanted to add an importer. I wasn't able to attach it.

Here's the importer that was created:

$feeds_importer = new stdClass();
$feeds_importer->disabled = FALSE; /* Edit this to true to make a default feeds_importer disabled initially */
$feeds_importer->api_version = 1;
$feeds_importer->id = 'hotel_recommendations';
$feeds_importer->config = array(
  'name' => 'Hotel recommendations',
  'description' => '',
  'fetcher' => array(
    'plugin_key' => 'FeedsHTTPFetcher',
    'config' => array(
      'auto_detect_feeds' => FALSE,
      'use_pubsubhubbub' => FALSE,
      'designated_hub' => '',
      'request_timeout' => NULL,
      'auto_scheme' => 'http',
      'accept_invalid_cert' => FALSE,
      'cache_http_result' => TRUE,
    ),
  ),
  'parser' => array(
    'plugin_key' => 'FeedsSyndicationParser',
    'config' => array(),
  ),
  'processor' => array(
    'plugin_key' => 'FeedsNodeProcessor',
    'config' => array(
      'expire' => -1,
      'author' => 0,
      'authorize' => TRUE,
      'mappings' => array(),
      'insert_new' => 1,
      'update_existing' => 0,
      'update_non_existent' => 'skip',
      'input_format' => NULL,
      'skip_hash_check' => FALSE,
      'bundle' => NULL,
      'language' => 'und',
    ),
  ),
  'content_type' => '',
  'update' => 0,
  'import_period' => 1800,
  'expire_period' => 3600,
  'import_on_create' => TRUE,
  'process_in_background' => FALSE,
);

Yes, i18n_node is enabled.

Yes, it works!

No more error on adding or editing an feeds importer.

Thanks a lot!