Did you check to see if all the files were present on the site? you maybe missing that file that its referring to. Or if that file is a file from a hack then to disable all the hooks globally download your config.php file you will find it in the forum/includes directory. Open it in an editor & find:
Just beneath it place this code:
Code:
define('DISABLE_HOOKS', true);
Save your config.php file and upload it back into your site overwriting the old one.