PHP Core Warning – yii\base\ErrorException

$_GET = [
    'random' => '1791372244',
];

$_COOKIE = [
    'topics-session' => '1791402017.531.16814.538675|d197bbbd1d400bd72372bc93068ad169',
    'PHPSESSID' => 'tmmjlir6c1q80q9lldcef9m5a3',
    '_csrf' => '3f55cf52fed229502570b3e6641559005af83467e686e5b8de66cdff1dda060ca:2:{i:0;s:5:"_csrf";i:1;s:32:"5usLssADZJ1fXMTjAQcNSxiR9RqctPd0";}',
];

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