PHP Core Warning – yii\base\ErrorException

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

$_COOKIE = [
    'PHPSESSID' => '8q9u9d6o45e5qiepi4qj6tlsg4',
    'topics-session' => '1765835858.163.16013.506714|d197bbbd1d400bd72372bc93068ad169',
    '_csrf' => '484a8fa7c3323242bc95480cf0c2ccc86bab496c1497656c4e3c38865d6a37baa:2:{i:0;s:5:"_csrf";i:1;s:32:"s91y5EPE-lNqBI2oNLWzf7pewV00VQkt";}',
];