PHP Core Warning – yii\base\ErrorException

$_GET = [
    'redirect_url' => '/yjds2016/cases/match',
];

$_COOKIE = [
    'topics-session' => '1791234183.492.16479.924635|d197bbbd1d400bd72372bc93068ad169',
    'PHPSESSID' => '5vc3cb89vsaljtd0c84c9011s0',
    '_csrf' => '6332f63a8620b0bd8df6bbf053e0375c3fb4d3464360e6ba1fa3aa681da70247a:2:{i:0;s:5:"_csrf";i:1;s:32:"pYWqQORYqKwTUzTyPpEvjQ2a8LZ2JMas";}',
];