Dear all; I fixed this problem which I reported in the below. Thanks! Best Regards, Soonho From: support-bounces@drupal.org [mailto:support-bounces@drupal.org] On Behalf Of Kim, Soonho (IFPRI) Sent: Monday, October 17, 2011 4:32 PM To: support@drupal.org Subject: [support] Fatal error: require_once() [function.require]: Failedopening required 'Text/Wiki/Mediawiki.php' Dear all; How are you? I am a new on Drupal. Recently, I got the final version of our project website from the commercial company and I created a development version of my Drupal, which is the exact same copy of the production server. I got the following errors when I accessed "wiki" and "blog"s. My wiki is made with "Book" module. Fatal error: require_once() [function.require <http://lnkd.info/wiki/function.require> ]: Failed opening required 'Text/Wiki/Mediawiki.php' (include_path=':.:/usr/lib/php:/usr/local/lib/php') in /usr/lib/php/Text/Wiki.php on line 473 You can check it out in my server : http://lnkd.info/wiki/agrodep-wiki I tried to fix it. I found that the file "Wiki.php" in the /usr/lib/php/Text/ folder. But, I don't know how to fix it. My guess is that I need to fix it in the Drupal instead of PHP file. Is there anyone who knows some clue or hint to fix this problem? Do I re-install new version of modules? Thanks for your help in advance. : ) Best Regards, Soonho