Why does phalcon output Undefined variable?

Question

Phalcon

the source
at first did everything, too, everything was deduced from the tutorial database,
then he created his own database, connected it and the warnings
started rolling Notice: Undefined variable: invo in .... 3
Warning: Invalid argument supplied for foreach() .... 3
index.volt

{{ content() }}
{% for contact in invo %}
    <p>{{ contact.name }}</p>
{% endfor %}

models/Invo.php

class Invo extends \Phalcon\Mvc\Model
{
  public function initialize(){
    $this->setSource('contact');
  }
}

InvoController.php

public function indexAction(){
    $invo = Invo::find();//при вар дампе значение не пусто, значит выводиться должно
    $this->view->setVar("contact", $invo);
  }
}

Everything is fine with the config.php, so if it didn't connect, it would display this "Table 'contact' doesn't exist in database when dumping meta-data for Invo"
The database connection string looks like this:

/**
 * Подключение базы данных
 */
$di->set('db', function() use ($config){
  return new DbAdapter($config["database"]->toArray()); //берём подключение из config.php
});

Answer 1

45 minutes of stupidity because of one line:
$this->view->setVar("invo", $invo);