Error

PHP Noticeyii\base\ErrorException

Trying to get property of non-object

$_GET = [
    'title' => '%E5%B0%8F%E7%9F%A5%E8%AF%86',
    'type' => 'academic',
    'number' => '2',
    'second' => '1',
];

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