Thread:Project:Support desk/Error in LanguageUtf8.php/reply

It sounds like you might be mixing old and new files. Please be sure to read all of the instructions on Manual:Upgrading as well as grabbing the latest version from Download.

Also, PHP4 is ancient and unsupported by the PHP developers or MediaWiki (the last version for PHP4 we released was the 1.6.x series, which is many years out of date). Please try to upgrade to PHP5 (5.1.x is required for MediaWiki). If this is not possible, I suggest switching hosting providers.