title: Cannot select the scala sdk when using Intellij after installed the scala plugin
body: <p>Everyone, thanks for your attention.</p>
  
  <p>I'm using Intellij IDEA 2017.2 in windows 7, with Scala plugin installed.(I downloaded directly from the <a href="https://plugins.jetbrains.com/plugin/1347-scala" rel="nofollow noreferrer">web</a> and installed it from local disk.)</p>
  
  <p>But when I wanna to add Scala sdk through "Project Structure-Global Libraries" , I clicked the menu "Scala sdk" which is shown in the picture below, it didn't appear by the popup window as expected, i.e, it didn't present anything.
  So I cannot select the Scala sdk.</p>
  
  <p><a href="https://i.stack.imgur.com/Znp2Y.png" rel="nofollow noreferrer">the picture describes the scenario</a></p>
  
  <p>What should I do to make it work in Intellij? My scala version is 2.12.2.
  Any advices will be appreciated.</p>