There is a problem configuring yii2 rbac and an internal error is reported.

I get an error when configuring rbac of yii2. Configure according to the method provided at this address
http://www.manks.top/yii2_fra...

An error will be reported when configuring the urlManager item in main.php, as long as it is set

<code>"urlManager" => [
     // 'class' => 'yii\rbac\DbManager', //这里记得用单引号而不是双引号 
],</code>

An error will be reported here

What exactly is going on?