Problems rendering page after enable PageCache

Hello guys,

I need help solving a problem, I’ve searched everywhere but cant find a way to solve.

After enabling PageCache on Behaviours method on my Controller, the page will only render symbols ( ��2����X-&) instead of the page content.

Here is the code on my controller:

public function behaviors()


        return [


                'class' => 'yii\filters\PageCache',

                'only' => ['item'],

                'duration' => 900,

                'variations' => [



                'dependency' => [

                    'class' => 'yii\caching\DbDependency',

                    'sql' => 'SELECT COUNT(*) FROM posts',





Can anyone help or give a tip on how to solve this?

Thank you for your time.