title: Yii2 OpenId Connect error - yii2-authclient returns 400 error "Token not provided" when I try to getUserAttributes()
body: <p>I'm implementing OpenId Connect into my Yii2 app using the yii2-authclient library. I can login and exchange the code for a token with no problems. I've followed most of the code examples on the web and set a successCallback function that gets called once a user successfully logs in. It looks like this:</p>
  
  <pre><code>public function successCallback(ClientInterface $client) 
  {
      $attributes = $client-&gt;getUserAttributes();
  }
  </code></pre>
  
  <p>This code gets called, but calling <code>getUserAttributes()</code> results in the following error:</p>
  
  <blockquote>
    <p>Exception – yii\authclient\InvalidResponseException<br>
    Request failed with code: 400, message:<br>
        {"error":"invalid_request","error_description":"Token not provided"}</p>
  </blockquote>
  
  <p>The logs on the id server show a blank client and user, with an error of <code>invalid_token</code>.</p>
  
  <p>I took a close look at the request I make and I see an <code>access_token</code> element. Any ideas what the problem might be? I can provide more information if necessary.</p>