title: Sources for Android API 23 Platform not found (Android Studio 2.0)
body: <p>Android Studio doesn't redirect me to API sources correctly. When I hit any function it decompiles .class file bytecode instead of accessing the right file from sdk/sources tree. 
  <a href="https://i.stack.imgur.com/7pywB.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7pywB.png" alt=""></a>
  Hitting "download" and "refreshing" options does nothing. It's particularly annoying for implementing listeners since it generates functions' headers without variables' manes from documentation (i.e. var1, var2 etc.). I have installed API 23 (SDK platform, tools, docs, sources). I have set compile and target SDK to 23.
   I tried to reinstall SDK tools, update AS from canary channel, invalidate cache but nothing helped so far. 
  I switched to API 21 and it works fine. </p>
  
  <p>What am I missing?</p>
  
  <p>My build.gradle:</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 23
      buildToolsVersion '23.0.2'
  
      defaultConfig {
          applicationId "com.myapp.app"
          minSdkVersion 10
          targetSdkVersion 23
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(include: ['*.jar'], dir: 'libs')
      testCompile 'junit:junit:4.12'
      compile 'com.android.support:appcompat-v7:23.3.0'
      compile 'com.android.support:design:23.3.0'
      compile 'com.squareup.picasso:picasso:2.5.2'
      compile project(':volley')
      compile 'com.jakewharton:butterknife:7.0.1'
  }
  </code></pre>
  
  <p>Below you can find gradle output for a blank project (without 3rd party libs) with the same API 23 set and the same behaviour.</p>
  
  <pre><code>Executing tasks: [clean, :app:generateDebugSources, :app:generateDebugAndroidTestSources, :app:mockableAndroidJar, :app:prepareDebugUnitTestDependencies]
  
  Configuration on demand is an incubating feature.
  Incremental java compilation is an incubating feature.
  :clean
  :app:clean
  :app:preBuild UP-TO-DATE
  :app:preDebugBuild UP-TO-DATE
  :app:checkDebugManifest
  :app:preReleaseBuild UP-TO-DATE
  :app:prepareComAndroidSupportAnimatedVectorDrawable2330Library
  :app:prepareComAndroidSupportAppcompatV72330Library
  :app:prepareComAndroidSupportDesign2330Library
  :app:prepareComAndroidSupportRecyclerviewV72330Library
  :app:prepareComAndroidSupportSupportV42330Library
  :app:prepareComAndroidSupportSupportVectorDrawable2330Library
  :app:prepareDebugDependencies
  :app:compileDebugAidl
  :app:compileDebugRenderscript
  :app:generateDebugBuildConfig
  :app:mergeDebugShaders
  :app:compileDebugShaders
  :app:generateDebugAssets
  :app:mergeDebugAssets
  :app:generateDebugResValues UP-TO-DATE
  :app:generateDebugResources
  :app:mergeDebugResources
  :app:processDebugManifest
  :app:processDebugResources
  :app:generateDebugSources
  :app:preDebugAndroidTestBuild UP-TO-DATE
  :app:prepareDebugAndroidTestDependencies
  :app:compileDebugAndroidTestAidl
  :app:processDebugAndroidTestManifest
  :app:compileDebugAndroidTestRenderscript
  :app:generateDebugAndroidTestBuildConfig
  :app:mergeDebugAndroidTestShaders
  :app:compileDebugAndroidTestShaders
  :app:generateDebugAndroidTestAssets
  :app:mergeDebugAndroidTestAssets
  :app:generateDebugAndroidTestResValues UP-TO-DATE
  :app:generateDebugAndroidTestResources
  :app:mergeDebugAndroidTestResources
  :app:processDebugAndroidTestResources
  :app:generateDebugAndroidTestSources
  :app:mockableAndroidJar
  :app:preDebugUnitTestBuild UP-TO-DATE
  :app:prepareDebugUnitTestDependencies
  
  BUILD SUCCESSFUL
  </code></pre>