PHP Core Warning – yii\base\ErrorException

$_GET = [
    'page' => '436',
];

$_COOKIE = [
    'PHPSESSID' => 'esfmr8dm5eh2iab29baqde6ih3',
    '_csrf' => '3ed988f39919e57f17e647a8d506e18e34b991880c13dcc52306960c98311816a:2:{i:0;s:5:"_csrf";i:1;s:32:"F4xhpb7oSgiFTgEPgQxL6QCrJvRRegX3";}',
];

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