title: How to fix Scala compilation errors? Unable to compile in idea 13.1.5
body: <p>I'm trying to create a very simple scala application in <code>idea 13.1.5.</code></p>
  
  <pre><code>java version "1.7.0_67"
  Java(TM) SE Runtime Environment (build 1.7.0_67-b01)
  Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)
  
  Scala Version is 2.11.2-1
  </code></pre>
  
  <p>During the <strong>compilation</strong>, it always complains the following <strong>errors:</strong></p>
  
  <pre><code>Error:scalac: Error: object java.lang.Object in compiler mirror not found.
  scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
      at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:17)
      at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:18)
      at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:53)
      at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
      at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
      at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:66)
      at scala.reflect.internal.Mirrors$RootsBase.getClassByName(Mirrors.scala:102)
      at scala.reflect.internal.Mirrors$RootsBase.getRequiredClass(Mirrors.scala:105)
      at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass$lzycompute(Definitions.scala:257)
      at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass(Definitions.scala:257)
      at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1376)
      at scala.tools.nsc.Global$Run.&lt;init&gt;(Global.scala:1229)
      at xsbt.CachedCompiler0$$anon$2.&lt;init&gt;(CompilerInterface.scala:116)
      at xsbt.CachedCompiler0.run(CompilerInterface.scala:116)
      at xsbt.CachedCompiler0.run(CompilerInterface.scala:102)
      at xsbt.CompilerInterface.run(CompilerInterface.scala:27)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:606)
      at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:102)
      at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:48)
      at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:41)
      at org.jetbrains.jps.incremental.scala.local.IdeaIncrementalCompiler.compile(IdeaIncrementalCompiler.scala:28)
      at org.jetbrains.jps.incremental.scala.local.LocalServer.compile(LocalServer.scala:26)
      at org.jetbrains.jps.incremental.scala.remote.Main$.make(Main.scala:64)
      at org.jetbrains.jps.incremental.scala.remote.Main$.nailMain(Main.scala:22)
      at org.jetbrains.jps.incremental.scala.remote.Main.nailMain(Main.scala)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:606)
      at com.martiansoftware.nailgun.NGSession.run(NGSession.java:319)
  </code></pre>