I got this message suddenly on vBulletin forum. When i run "Suspect file versions" from AdminCP / Maintenance / Diagnostics

it returned that this file /includes/functions_wysiwyg.php was not found. So i had to download my vbulletin script again and upload this file, then it was fixed

Warning: require_once([path]/includes/functions_wysiwyg.php) [function.require-once]: failed to open stream: No such file or directory in [path]/newreply.php on line 296

Fatal error:  require_once() [function.require]: Failed opening required '/home/admin/*/includes/functions_wysiwyg.php' (include_path='.:/usr/share/pear/') in /home/admin/*/newreply.php on line 296