title: Internal Error Java program Intellij
body: <p>I have the error while executing the java program in Intellij IDE. Any thoughts what might be the issue.</p>
  
  <pre><code>Error:Internal error: (java.lang.IllegalArgumentException) No enum constant org.jetbrains.jps.model.java.LanguageLevel.JDK_1_9
  java.lang.IllegalArgumentException: No enum constant org.jetbrains.jps.model.java.LanguageLevel.JDK_1_9
      at java.lang.Enum.valueOf(Enum.java:238)
      at org.jetbrains.jps.model.java.LanguageLevel.valueOf(LanguageLevel.java:21)
      at org.jetbrains.jps.model.serialization.java.JpsJavaModelSerializerExtension$JavaProjectExtensionSerializer.loadExtension(JpsJavaModelSerializerExtension.java:285)
      at org.jetbrains.jps.model.serialization.java.JpsJavaModelSerializerExtension$JavaProjectExtensionSerializer.loadExtension(JpsJavaModelSerializerExtension.java:268)
      at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadComponents(JpsLoaderBase.java:59)
      at org.jetbrains.jps.model.serialization.JpsProjectLoader.a(JpsProjectLoader.java:119)
      at org.jetbrains.jps.model.serialization.JpsProjectLoader.loadProject(JpsProjectLoader.java:98)
      at org.jetbrains.jps.model.serialization.impl.JpsSerializationManagerImpl.loadModel(JpsSerializationManagerImpl.java:41)
      at org.jetbrains.jps.cmdline.JpsModelLoaderImpl.loadModel(JpsModelLoaderImpl.java:45)
      at org.jetbrains.jps.cmdline.BuildRunner.load(BuildRunner.java:71)
      at org.jetbrains.jps.cmdline.BuildSession.runBuild(BuildSession.java:198)
      at org.jetbrains.jps.cmdline.BuildSession.run(BuildSession.java:113)
      at org.jetbrains.jps.cmdline.BuildMain$MyMessageHandler$1.run(BuildMain.java:133)
      at org.jetbrains.jps.service.impl.SharedThreadPoolImpl$1.run(SharedThreadPoolImpl.java:41)
      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
      at java.util.concurrent.FutureTask.run(FutureTask.java:266)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at java.lang.Thread.run(Thread.java:745)
  </code></pre>
  
  <p>I have configured <code>JDK1_8</code>. But still it is showing as <code>1_9</code>.</p>