title: IntelliJ IDEA Test Coverage window doesn't show
body: <p>I'm using Spring Boot project with the last version of IntelliJ IDEA (2018.2.1 Ultimate Edition).</p>
  
  <p>When I run all my test with coverage the Coverage window doesn't show, and there's no percentage beside my main classes.</p>
  
  <p>I've tried enabling the coverage window by going to <code>View -&gt; Tool Windows -&gt; Coverage</code>, but the coverage tab is disabled (not clickable).</p>
  
  <p><a href="https://i.stack.imgur.com/luGgV.png" rel="noreferrer"><img src="https://i.stack.imgur.com/luGgV.png" alt="enter image description here"></a></p>
  
  <p>If I remember correctly the coverage was working fine before I update IntelliJ. Is that a bug with the last version ?</p>
  
  <p><strong>Edit</strong><br>
  the coverage plugin is already installed<br>
  <a href="https://i.stack.imgur.com/dmCeP.png" rel="noreferrer"><img src="https://i.stack.imgur.com/dmCeP.png" alt="enter image description here"></a></p>