title: NoClassDefFoundError: rx.subscriptions.CompositeSubscription
body: <p>I've an Android project where I used <code>rxjava</code> and <code>rxAndroid</code>. I suddenly started to get that crash <code>"NoClassDefFoundError: rx.subscriptions.CompositeSubscription"</code></p>
  
  <p>I've tried to look it online but I couldn't find a solution</p>
  
  <pre><code>java.lang.ExceptionInInitializerError
  at rx.plugins.RxJavaSchedulersHook.createIoScheduler(RxJavaSchedulersHook.java:84)
  at rx.plugins.RxJavaSchedulersHook.createIoScheduler(RxJavaSchedulersHook.java:72)
  at rx.schedulers.Schedulers.&lt;init&gt;(Schedulers.java:70)
  at rx.schedulers.Schedulers.getInstance(Schedulers.java:47)
  at rx.schedulers.Schedulers.newThread(Schedulers.java:108)
  at com.myPackage.controllers.modelsControllers.CountriesController.loadCountries(CountriesController.java:121)
  at com.myPackage.views.fragments.ChatFragment.onCreateView(ChatFragment.java:57)
  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:829)
  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1035)
  at android.app.BackStackRecord.run(BackStackRecord.java:635)
  at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1397)
  at android.app.Activity.performStart(Activity.java:5017)
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2032)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
  at android.app.ActivityThread.access$600(ActivityThread.java:130)
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
  at android.os.Handler.dispatchMessage(Handler.java:99)
  at android.os.Looper.loop(Looper.java:137)
  at android.app.ActivityThread.main(ActivityThread.java:4745)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:511)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
  at dalvik.system.NativeStart.main(Native Method)
  Caused by: java.lang.NoClassDefFoundError: rx.subscriptions.CompositeSubscription
  at rx.internal.schedulers.CachedThreadScheduler$CachedWorkerPool.&lt;init&gt;(CachedThreadScheduler.java:48)
  at rx.internal.schedulers.CachedThreadScheduler.&lt;clinit&gt;(CachedThreadScheduler.java:139)
  at rx.plugins.RxJavaSchedulersHook.createIoScheduler(RxJavaSchedulersHook.java:84) 
  at rx.plugins.RxJavaSchedulersHook.createIoScheduler(RxJavaSchedulersHook.java:72) 
  at rx.schedulers.Schedulers.&lt;init&gt;(Schedulers.java:70) 
  at rx.schedulers.Schedulers.getInstance(Schedulers.java:47) 
  at rx.schedulers.Schedulers.newThread(Schedulers.java:108) 
  at com.myPackage.controllers.modelsControllers.CountriesController.loadCountries(CountriesController.java:121) 
  at com.myPackage.views.fragments.ChatFragment.onCreateView(ChatFragment.java:57) 
  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:829) 
  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1035) 
  at android.app.BackStackRecord.run(BackStackRecord.java:635) 
  at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1397) 
  at android.app.Activity.performStart(Activity.java:5017) 
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2032) 
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 
  at android.app.ActivityThread.access$600(ActivityThread.java:130) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 
  at android.os.Handler.dispatchMessage(Handler.java:99) 
  at android.os.Looper.loop(Looper.java:137) 
  at android.app.ActivityThread.main(ActivityThread.java:4745) 
  at java.lang.reflect.Method.invokeNative(Native Method) 
  at java.lang.reflect.Method.invoke(Method.java:511) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
  at dalvik.system.NativeStart.main(Native Method) 
  </code></pre>
  
  <p>I didn't really change anything in the classes which is throwing exception which confuse me. </p>
  
  <p>In my build.gradle, I've compile 'io.reactivex:rxandroid:1.2.1'
      compile 'io.reactivex:rxjava:1.1.6'</p>
  
  <p>in my observable, I send http request using okHttp, and the exact line that throws exception is </p>
  
  <pre><code>subscribeOn(Schedulers.newThread()).observeOn(AndroidSchedulers.mainThread());
  </code></pre>
  
  <p>I need any suggestion ^^, and if you have any question please let me know. </p>
  
  <p>Also if possible, can anyone explain what does that crash even mean?
  Thanks.</p>
  
  <p><strong>EDIT</strong>
  my build.gradle have those</p>
  
  <pre><code>    compile 'io.reactivex:rxandroid:1.2.1'
  // Because RxAndroid releases are few and far between, it is recommended you also
  // explicitly depend on RxJava's latest version for bug fixes and new features.
      compile 'io.reactivex:rxjava:1.1.6'
      compile 'com.jakewharton.rxbinding:rxbinding-support-v4:0.4.0'
      compile 'com.trello:rxlifecycle:0.6.1'
  // If you want pre-written Activities and Fragments you can subclass as providers
      compile 'com.trello:rxlifecycle-components:0.6.1'
  
      compile 'com.mlsdev.rximagepicker:library:1.1.9'
      compile 'com.github.zellius:rxlocationmanager:0.1.1'
      compile 'com.sdoward:rxgooglemaps:1.0@aar'
  </code></pre>