Warning: require(Text/Diff.php) [function.require]: failed to open stream: No such file or directory in /home/wudifwe/public_html/wp-includes/wp-diff.php on line 4

Fatal error: require() [function.require]: Failed opening required 'Text/Diff.php' (include_path='/usr/lib/php:/usr/local/lib/php:.:/usr/lib/php/:/usr/local/lib/php/') in /home/wudifwe/public_html/wp-includes/wp-diff.php on line 4