NoClassDefFoundError: @ FacebookSocialNetwork class

In below line at runtime app is going to crash ..... with NoClassDefFoundError
" FacebookSocialNetwork fbNetwork = new FacebookSocialNetwork(this, fbScope); "

E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NoClassDefFoundError: com.github.gorbin.asne.facebook.FacebookSocialNetwork$1
at com.github.gorbin.asne.facebook.FacebookSocialNetwork.(FacebookSocialNetwork.java:87)
at a2a.example.testapp.MainFragment.onCreateView(MainFragment.java:75)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1016)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1197)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1562)
at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:330)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:511)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1167)
at android.app.Activity.performStart(Activity.java:5192)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2279)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2358)
at android.app.ActivityThread.access$600(ActivityThread.java:156)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1340)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:153)
at android.app.ActivityThread.main(ActivityThread.java:5299)
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:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)