I get the following Error when i try to open an index created with Java Nutch Lucene:

Fatal error: Uncaught exception 'Zend_Search_Lucene_Exception' with message 'failed to open stream: Is a directory' in /home/httpd/vhosts/www.com/httpdocs/Zend/Search/Lucene/Storage/File/Filesystem.php:69 Stack trace: #0 /home/httpd/vhosts/www.com/httpdocs/Zend/Search/Lucene/Storage/Directory/Filesystem.php(351): Zend_Search_Lucene_Storage_File_Filesystem->__construct('crawl/segments') #1 /home/httpd/vhosts/www.com/httpdocs/Zend/Search/Lucene.php(245): Zend_Search_Lucene_Storage_Directory_Filesystem->getFileObject('segments', false) #2 /home/httpd/vhosts/www.com/httpdocs/Zend/Search/Lucene.php(416): Zend_Search_Lucene::getActualGeneration(Object(Zen d_Search_Lucene_Storage_Directory_Filesystem)) #3 /home/httpd/vhosts/www.com/httpdocs/Zend/Search/Lucene.php(186): Zend_Search_Lucene->__construct('crawl', false) #4 /home/httpd/vhosts/www.com/httpdocs/crawl.php(17): Zend_Search_Lucene:pen('crawl') #5 {main} thrown in /home/httpd/vhosts/www.com/httpdocs/Zend/Search/Lucene/Storage/File/Filesystem.php on line 69

I crawled and idexex the files with java nutch and copied then the generatet folders to the online folder:

the script which generates the error is the following:

require_once 'Zend/Search/Lucene.php';
$indexPath = 'crawl';
$index = Zend_Search_Lucene:pen($indexPath);

nutch 0.9
lucene ?
Zend Framework 1.5