Error

PHP Noticeyii\base\ErrorException

Trying to get property of non-object

$_GET = [
    'title' => '%E6%96%87%E7%8C%AE%E5%BA%93',
    'type' => 'academic',
    'number' => '1',
    'second' => '3',
];

$_SESSION = [
    '__flash' => [],
];