Cho mình hỏi vì sao mình bị gặp lỗ này Server Error Server Error Validate class not found from basename 'EmailAddress' Zend_Validate::is() in XenForo/DataWriter/User.php at line 572 XenForo_DataWriter_User->_verifyEmail() call_user_func_array() in XenForo/DataWriter.php at line 965 XenForo_DataWriter->_runVerificationCallback() in XenForo/DataWriter.php at line 720 XenForo_DataWriter->_isFieldValueValid() in XenForo/DataWriter.php at line 638 XenForo_DataWriter->set() in XenForo/DataWriter.php at line 978 XenForo_DataWriter->bulkSet() in XenForo/Install/Model/Install.php at line 216 XenForo_Install_Model_Install->insertAdministrator() in XenForo/Install/Controller/Install.php at line 274 XenForo_Install_Controller_Install->actionStep3b() in XenForo/FrontController.php at line 310 XenForo_FrontController->dispatch() in XenForo/FrontController.php at line 132 XenForo_FrontController->run() in C:/xampp/htdocs/beta/install/index.php at line 18