Tell me what kind of error is this?

Question

Yii

Good day)))))
I have such a problem. I did everything according to the lesson, but when I write the last line

<!--кнопка вверх-->
<?= common\widgets\ScrollupWidget::widget() ?>
<?php $this->endBody() ?>

an error pops up. Did according to the lesson klisl.com/scrolltop.html

Answer 1

search not working?
https://yandex.ru/search/?text=cannot%20create%20s...

Answer 2

Run OpenServer as administrator, he does not have enough rights. Well, either abandon symlink

'assetManager' => [
            //'linkAssets' => true,
        ],