title: Yii2 json_encode Invalid UTF-8 sequence in argument
body: <p>I am trying to signup, after i made a composer update for Yii2 and I get the following error:</p>
  
  <pre><code>PHP Warning – yii\base\ErrorException
  
  json_encode(): Invalid UTF-8 sequence in argument
  </code></pre>
  
  <p>The error is where the model attributes array is encoded as a json:</p>
  
  <pre><code>Json::encode($this-&gt;owner-&gt;attributes)
  </code></pre>