Ошибка при авторизации в админке

Warning: base64_decode() has been disabled for security reasons in /home/flat/domains/esial.ru/public_html/libraries/src/Session/Session.php on line 668
Error: Failed to start application: Call to a member function get() on boolean
Fatal error: Uncaught Error: __clone method called on non-object in /home/flat/domains/esial.ru/public_html/libraries/src/Session/Session.php:386 Stack trace: #0 /home/flat/domains/esial.ru/public_html/libraries/joomla/session/handler/native.php(189): Joomla\CMS\Session\Session->getData() #1 [internal function]: JSessionHandlerNative->save() #2 {main} thrown in /home/flat/domains/esial.ru/public_html/libraries/src/Session/Session.php on line 386


Весь гугл перерыл .. ничего похожего не нашел ..

вот эта строка
foreach ($migratableKeys as $migratableKey)
{
if (!empty($_SESSION['__default'][$migratableKey]))
{ <----- 688 строка
// Don't overwrite existing session data
if (!is_null($this->data->get('__default.' . $migratableKey, null)))
{
continue;
}

$this->data->set('__default.' . $migratableKey, $_SESSION['__default'][$migratableKey]);
unset($_SESSION['__default'][$migratableKey]);
}
}