Hello, this is my code, and in attachment you can find the generated CSV.
Turned on also the debug mode, but nothing changed.
As you can see is empty 
<?php
/**
 * @package  HikaShop for Joomla!
 * @version  2.1.3
 * @author  hikashop.com
 * @copyright  (C) 2010-2013 HIKARI SOFTWARE. All rights reserved.
 * @license  GNU/GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
 */
defined('_JEXEC') or die('Restricted access');
?><?php
while(ob_get_level() > 1)
  ob_end_clean();
$config =& hikashop_config();
$format = $config->get('export_format','csv');
$separator = $config->get('csv_separator',';');
$force_quote = $config->get('csv_force_quote',1);
$export = hikashop_get('helper.spreadsheet');
$export->init($format, 'hikashopexport', $separator, $force_quote);
$characteristic = hikashop_get('class.characteristic');
$classProduct = hikashop_get('class.product');
$characteristic->loadConversionTables($this);
$db = JFactory::getDBO();
if(version_compare(JVERSION,'3.0','<')){
  $columnsTable = $db->getTableFields(hikashop_table('product'));
  $columnsArray = reset($columnsTable);
} else {
  $columnsArray = $db->getTableColumns(hikashop_table('product'));
}
$columnsArray['categories_ordering'] = 'categories_ordering';
$columns = $products_columns = array_keys($columnsArray);
$product_table_count = count($columns);
$columns = array_merge($columns, array(
  'parent_category' => 'parent_category',
  'categories_image' => 'categories_image',
  'categories' => 'categories',
  'price_value' => 'price_value',
  'price_currency_id' => 'price_currency_id',
  'price_min_quantity' => 'price_min_quantity',
  'price_access' => 'price_access',
  'files' => 'files',
  'images' => 'images',
  'related' => 'related',
  'options' => 'options'
));
$characteristicsColumns = array();
if(!empty($this->characteristics)) {
  foreach($this->characteristics as $characteristic) {
    if(empty($characteristic->characteristic_parent_id)) {
      $columns[$characteristic->characteristic_value] = $characteristic->characteristic_value;
      $characteristicsColumns[] = $characteristic->characteristic_value;
    }
  }
}
$after_category_count = count($columns)-($product_table_count+3);
$export->writeline($columns);
if(!empty($this->categories)) {
  foreach($this->categories as $category) {
    $data = array();
    for($i = 0; $i < $product_table_count; $i++)
      $data[] = '';
    if(!empty($category->category_parent_id) && isset($this->categories[$category->category_parent_id]))
      $data[] = $this->categories[$category->category_parent_id]->category_name;
    else
      $data[] = '';
    if(!empty($category->file_path))
       $data[] = $category->file_path;
    else
      $data[] = '';
    $data[] = $category->category_name;
    for($i = 0; $i < $after_category_count; $i++)
      $data[] = '';
$export->writeline($data);
  }
}
if(!empty($this->products)) {
  foreach($this->products as $k => $product) {
    if($product->product_type == 'variant')
      $this->products[$k]->product_parent_id = $this->products[$product->product_parent_id]->product_code;
  }
  foreach($this->products as $product) {
    $data = array();
    foreach($products_columns as $column) {
      if(!empty($product->$column) && is_array($product->$column))
        $product->$column = implode($separator,$product->$column);
      $data[] = @$product->$column;
    }
    $categories = array();
    if(!empty($product->categories)) {
      foreach($product->categories as $category) {
        if(!empty($this->categories[$category]))
          $categories[] = str_replace(array('"',',',';'), array('""','\\,','\\;'), $this->categories[$category]->category_name);
      }
    }
    $data[] = '';
    $data[] = '';
    if(!empty($categories))
      $data[] = implode($separator,$categories);
    else
      $data[] = '';
    $values = array();
    $codes = array();
    $qtys = array();
    $accesses = array();
    if(!empty($product->prices)) {
      foreach($product->prices as $price) {
        $values[] = $price->price_value;
        $codes[] = $this->currencies[$price->price_currency_id]->currency_code;
        $qtys[] = $price->price_min_quantity;
        $accesses[] = $price->price_access;
      }
    }
    if(empty($values)) {
      $data[] = '';
      $data[] = '';
      $data[] = '';
      $data[] = '';
    } else {
      $data[] = implode('|', $values);
      $data[] = implode('|', $codes);
      $data[] = implode('|', $qtys);
      $data[] = implode('|', $accesses);
    }
    $files = array();
    if(!empty($product->files)) {
      foreach($product->files as $file) {
        $files[] = str_replace(array('"',',',';'), array('""','\\,','\\;'), $file->file_path);
      }
    }
    if(empty($files)) {
      $data[] = '';
    } else {
      $data[] = implode($separator, $files);
    }
    $images = array();
    if(!empty($product->images)) {
      foreach($product->images as $image) {
        $images[] = str_replace(array('"',',',';'), array('""','\\,','\\;'), $image->file_path);
      }
    }
    if(empty($images)) {
      $data[] = '';
    } else {
      $data[] = implode($separator, $images);
    }
    $related = array();
    if(!empty($product->related)) {
      foreach($product->related as $rel) {
        if(!isset($this->products[$rel]->product_code)) $this->products[$rel] = $classProduct->get($rel);
        $related[] = str_replace(array('"',',',';'), array('""','\\,','\\;'), @$this->products[$rel]->product_code);
      }
    }
    if(empty($related)) {
      $data[] = '';
    } else {
      $data[] = implode($separator, $related);
    }
    $options = array();
    if(!empty($product->options)) {
      foreach($product->options as $rel) {
        if(!isset($this->products[$rel]->product_code)) $this->products[$rel] = $classProduct->get($rel);
        $options[] = str_replace(array('"',',',';'), array('""','\\,','\\;'), @$this->products[$rel]->product_code);
      }
    }
    if(empty($options)) {
      $data[] = '';
    } else {
      $data[] = implode($separator, $options);
    }
    if(!empty($product->variant_links)) {
      $characteristics = array();
      if(!empty($characteristicsColumns)) {
        foreach($product->variant_links as $char_id) {
          if(!empty($this->characteristics[$char_id])) {
            $char = $this->characteristics[$char_id];
            if(!empty($this->characteristics[$char->characteristic_parent_id])) {
              $key = $this->characteristics[$char->characteristic_parent_id]->characteristic_value;
              $characteristics[$key] = str_replace('"','""',$char->characteristic_value);
            }
          }
        }
        foreach($characteristicsColumns as $characteristic){
          $data[] = @$characteristics[$characteristic];
        }
      }
    } elseif(!empty($characteristicsColumns)) {
      for($i = 0; $i < count($characteristicsColumns); $i++) {
        $data[] = '';
      }
    }
    $export->writeLine($data);
  }
}
$export->send();
exit;