PHP Core Warning – yii\base\ErrorException

$_GET = [
    'random' => '1790932126',
];

$_COOKIE = [
    'topics-session' => '1790982659.624.16480.659427|d197bbbd1d400bd72372bc93068ad169',
    'PHPSESSID' => 'llrev9ft9p161s6lhngqm52c67',
    '_csrf' => '3af24cc1444c73272e62c8ecc38336978356c667e3a55da10ba4d967b31d53cea:2:{i:0;s:5:"_csrf";i:1;s:32:"bxsOAM1sgVGWvnXrz--oYE3nWXGsvgC2";}',
];

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