Fatal Exception : java.lang.NoClassDefFoundError : rt

Question

Fatal Exception: java.lang.NoClassDefFoundError: rt
   at rs.(SourceFile:17)
   at android.support.v7.widget.RecyclerView.onSaveInstanceState(SourceFile:201)
   at android.view.View.dispatchSaveInstanceState(View.java:13651)
   at android.view.ViewGroup.dispatchFreezeSelfOnly(ViewGroup.java:2835)
   at android.support.v7.widget.RecyclerView.dispatchSaveInstanceState(SourceFile:220)
   at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:2821)
   at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:2821)
   at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:2821)
   at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:2821)
   at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:2821)
   at android.view.View.saveHierarchyState(View.java:13634)
   at android.support.v4.app.FragmentManagerImpl.saveFragmentViewState(FragmentManager.java:2594)
   at android.support.v4.app.FragmentManagerImpl.saveFragmentBasicState(FragmentManager.java:2615)
   at android.support.v4.app.FragmentManagerImpl.saveAllState(FragmentManager.java:2678)
   at android.support.v4.app.FragmentController.saveAllState(FragmentController.java:134)
   at android.support.v4.app.FragmentActivity.onSaveInstanceState(FragmentActivity.java:571)
   at android.support.v7.app.AppCompatActivity.onSaveInstanceState(AppCompatActivity.java:509)
   at android.app.Activity.performSaveInstanceState(Activity.java:1229)
   at android.app.Instrumentation.callActivityOnSaveInstanceState(Instrumentation.java:1229)
   at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:3390)
   at android.app.ActivityThread.handleStopActivity(ActivityThread.java:3449)
   at android.app.ActivityThread.access$1200(ActivityThread.java:169)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1307)
   at android.os.Handler.dispatchMessage(Handler.java:102)
   at android.os.Looper.loop(Looper.java:146)
   at android.app.ActivityThread.main(ActivityThread.java:5487)
   at java.lang.reflect.Method.invokeNative(Method.java)
   at java.lang.reflect.Method.invoke(Method.java:515)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
   at dalvik.system.NativeStart.main(NativeStart.java)