IntelliJ IDEA 2016: Please choose persistence unit
<p>I try to atomatic generate entities by IntelliJ IDEA but not success.</p>

<p>error: Please choose presistence unit.</p>

<p><a href="https://i.stack.imgur.com/ZOWyZ.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/ZOWyZ.jpg" alt="enter image description here"></a></p>

<p>Help me generate entity and mapping files.</p>