CommandInvokationFailure: Unable to convert classes into dex format

I am trying to integrate Google play Games service into my project, but it is showing some errors which i cant understand as i am not too familiar with android development.

Here is my log:


CommandInvokationFailure: Unable to convert classes into dex format. See the Console for details.
/Library/Java/JavaVirtualMachines/jdk1.8.0_91.jdk/Contents/Home/bin/java -Xmx2048M -Dcom.android.sdkmanager.toolsdir="/Users/rajeevrajani/Library/Android/sdk/tools" -Dfile.encoding=UTF8 -jar "/Applications/Unity/PlaybackEngines/AndroidPlayer/Tools/sdktools.jar" -

stderr[
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zznm;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zznn;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzno;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzno$zza;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zznp;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zznq;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzqi;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzqi$zza;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzqj;
9 errors; aborting
]
stdout[
processing archive /Users/rajeevrajani/Documents/Development/Unity Projects/ADMOB ADS/Temp/StagingArea/android-libraries/MainLibProj/libs/./play-games-plugin-support.jar...
ignored resource META-INF/
ignored resource META-INF/MANIFEST.MF
ignored resource com/
ignored resource com/google/
ignored resource com/google/games/
ignored resource com/google/games/bridge/
processing com/google/games/bridge/BuildConfig.class...
processing com/google/games/bridge/NativeBridgeActivity.class...
processing com/google/games/bridge/TokenFragment.class...
processing com/google/games/bridge/TokenFragment$1.class...
processing com/google/games/bridge/TokenFragment$TokenRequest.class...
processing com/google/games/bridge/TokenPendingResult.class...
processing com/google/games/bridge/TokenResult.class...
processing archive /Users/rajeevrajani/Documents/Development/Unity Projects/ADMOB ADS/Temp/StagingArea/android-libraries/appcompat-v7-23.1.1/bin/classes.jar...
ignored resource .readme
ignored resource META-INF/
ignored resource META-INF/MANIFEST.MF
ignored resource android/
ignored resource android/support/
ignored resource android/support/v7/
ignored resource android/support/v7/app/
processing android/support/v7/app/ActionBar.class...
processing android/support/v7/app/ActionBar$DisplayOptions.class...
processing android/support/v7/app/ActionBar$LayoutParams.class...
processing android/support/v7/app/ActionBar$NavigationMode.class...
processing android/support/v7/app/ActionBar$OnMenuVisibilityListener.class...
processing android/support/v7/app/ActionBar$OnNavigationListener.class...
processing android/support/v7/app/ActionBar$Tab.class...
processing android/support/v7/app/ActionBar$TabListener.class...
processing android/support/v7/app/ActionBarActivity.class...
processing android/support/v7/app/ActionBarDrawerToggle.class...
processing android/support/v7/app/ActionBarDrawerToggle$1.class...
processing android/support/v7/app/ActionBarDrawerToggle$Delegate.class...
processing android/support/v7/app/ActionBarDrawerToggle$DelegateProvider.class...
processing android/support/v7/app/ActionBarDrawerToggle$DrawerArrowDrawableToggle.class...
processing android/support/v7/app/ActionBarDrawerToggle$DrawerToggle.class...
processing android/support/v7/app/ActionBarDrawerToggle$DummyDelegate.class...
processing android/support/v7/app/ActionBarDrawerToggle$HoneycombDelegate.class...
processing android/support/v7/app/ActionBarDrawerToggle$JellybeanMr2Delegate.class...
processing android/support/v7/app/ActionBarDrawerToggle$ToolbarCompatDelegate.class...
processing android/support/v7/app/ActionBarDrawerToggleHoneycomb.class...
processing android/support/v7/app/ActionBarDrawerToggleHoneycomb$SetIndicatorInfo.class...
processing android/support/v7/app/AlertController.class...
processing android/support/v7/app/AlertController$1.class...
processing android/support/v7/app/AlertController$2.class...
processing android/support/v7/app/AlertController$3.class...
processing android/support/v7/app/AlertController$4.class...
processing android/support/v7/app/AlertController$5.class...
processing android/support/v7/app/AlertController$AlertParams.class...
processing android/support/v7/app/AlertController$AlertParams$1.class...
processing android/support/v7/app/AlertController$AlertParams$2.class...
processing android/support/v7/app/AlertController$AlertParams$3.class...
processing android/support/v7/app/AlertController$AlertParams$4.class...
processing android/support/v7/app/AlertController$AlertParams$OnPrepareListViewListener.class...
processing android/support/v7/app/AlertController$ButtonHandler.class...
processing android/support/v7/app/AlertController$CheckedItemAdapter.class...
processing android/support/v7/app/AlertDialog.class...
processing android/support/v7/app/AlertDialog$Builder.class...
processing android/support/v7/app/AppCompatActivity.class...
processing android/support/v7/app/AppCompatCallback.class...
processing android/support/v7/app/AppCompatDelegate.class...
processing android/support/v7/app/AppCompatDelegateImplBase.class...
processing android/support/v7/app/AppCompatDelegateImplBase$1.class...
processing android/support/v7/app/AppCompatDelegateImplBase$ActionBarDrawableToggleImpl.class...
processing android/support/v7/app/AppCompatDelegateImplBase$AppCompatWindowCallbackBase.class...
processing android/support/v7/app/AppCompatDelegateImplV11.class...
processing android/support/v7/app/AppCompatDelegateImplV14.class...
processing android/support/v7/app/AppCompatDelegateImplV14$AppCompatWindowCallbackV14.class...
processing android/support/v7/app/AppCompatDelegateImplV23.class...
processing android/support/v7/app/AppCompatDelegateImplV23$AppCompatWindowCallbackV23.class...
processing android/support/v7/app/AppCompatDelegateImplV7.class...
processing android/support/v7/app/AppCompatDelegateImplV7$1.class...
processing android/support/v7/app/AppCompatDelegateImplV7$2.class...
processing android/support/v7/app/AppCompatDelegateImplV7$3.class...
processing android/support/v7/app/AppCompatDelegateImplV7$4.class...
processing android/support/v7/app/AppCompatDelegateImplV7$5.class...
processing android/support/v7/app/AppCompatDelegateImplV7$5$1.class...
processing android/support/v7/app/AppCompatDelegateImplV7$6.class...
processing android/support/v7/app/AppCompatDelegateImplV7$ActionMenuPresenterCallback.class...
processing android/support/v7/app/AppCompatDelegateImplV7$ActionModeCallbackWrapperV7.class...
processing android/support/v7/app/AppCompatDelegateImplV7$ActionModeCallbackWrapperV7$1.class...
processing android/support/v7/app/AppCompatDelegateImplV7$ListMenuDecorView.class...
processing android/support/v7/app/AppCompatDelegateImplV7$PanelFeatureState.class...
processing android/support/v7/app/AppCompatDelegateImplV7$PanelFeatureState$SavedState.class...
processing android/support/v7/app/AppCompatDelegateImplV7$PanelFeatureState$SavedState$1.class...
processing android/support/v7/app/AppCompatDelegateImplV7$PanelMenuPresenterCallback.class...
processing android/support/v7/app/AppCompatDialog.class...
processing android/support/v7/app/AppCompatDialogFragment.class...
processing android/support/v7/app/AppCompatViewInflater.class...
processing android/support/v7/app/AppCompatViewInflater$DeclaredOnClickListener.class...
processing android/support/v7/app/NavItemSelectedListener.class...
processing android/support/v7/app/NotificationCompat.class...
processing android/support/v7/app/NotificationCompat$1.class...
processing android/support/v7/app/NotificationCompat$Builder.class...
processing android/support/v7/app/NotificationCompat$IceCreamSandwichExtender.class...
processing android/support/v7/app/NotificationCompat$JellybeanExtender.class...
processing android/support/v7/app/NotificationCompat$LollipopExtender.class...
processing android/support/v7/app/NotificationCompat$MediaStyle.class...
processing android/support/v7/app/NotificationCompatImpl21.class...
processing android/support/v7/app/NotificationCompatImplBase.class...
processing android/support/v7/app/ToolbarActionBar.class...
processing android/support/v7/app/ToolbarActionBar$1.class...
processing android/support/v7/app/ToolbarActionBar$2.class...
processing android/support/v7/app/ToolbarActionBar$ActionMenuPresenterCallback.class...
processing android/support/v7/app/ToolbarActionBar$MenuBuilderCallback.class...
processing android/support/v7/app/ToolbarActionBar$PanelMenuPresenterCallback.class...
processing android/support/v7/app/ToolbarActionBar$ToolbarCallbackWrapper.class...
processing android/support/v7/app/TwilightCalculator.class...
processing android/support/v7/app/TwilightManager.class...
processing android/support/v7/app/TwilightManager$1.class...
processing android/support/v7/app/TwilightManager$TwilightState.class...
processing android/support/v7/app/WindowDecorActionBar.class...
processing android/support/v7/app/WindowDecorActionBar$1.class...
processing android/support/v7/app/WindowDecorActionBar$2.class...
processing android/support/v7/app/WindowDecorActionBar$3.class...
processing android/support/v7/app/WindowDecorActionBar$ActionModeImpl.class...
processing android/support/v7/app/WindowDecorActionBar$TabImpl.class...
ignored resource android/support/v7/appcompat/
processing android/support/v7/appcompat/BuildConfig.class...
ignored resource android/support/v7/graphics/
ignored resource android/support/v7/graphics/drawable/
processing android/support/v7/graphics/drawable/DrawableUtils.class...
processing android/support/v7/graphics/drawable/DrawableWrapper.class...
processing android/support/v7/graphics/drawable/DrawerArrowDrawable.class...
processing android/support/v7/graphics/drawable/DrawerArrowDrawable$ArrowDirection.class...
ignored resource android/support/v7/text/
processing android/support/v7/text/AllCapsTransformationMethod.class...
ignored resource android/support/v7/transition/
processing android/support/v7/transition/ActionBarTransition.class...
ignored resource android/support/v7/view/
processing android/support/v7/view/ActionBarPolicy.class...
processing android/support/v7/view/ActionMode.class...
processing android/support/v7/view/ActionMode$Callback.class...
processing android/support/v7/view/CollapsibleActionView.class...
processing android/support/v7/view/ContextThemeWrapper.class...
processing android/support/v7/view/StandaloneActionMode.class...
processing android/support/v7/view/SupportActionModeWrapper.class...
processing android/support/v7/view/SupportActionModeWrapper$CallbackWrapper.class...
processing android/support/v7/view/SupportMenuInflater.class...
processing android/support/v7/view/SupportMenuInflater$InflatedOnMenuItemClickListener.class...
processing android/support/v7/view/SupportMenuInflater$MenuState.class...
processing android/support/v7/view/ViewPropertyAnimatorCompatSet.class...
processing android/support/v7/view/ViewPropertyAnimatorCompatSet$1.class...
processing android/support/v7/view/WindowCallbackWrapper.class...
ignored resource android/support/v7/view/menu/
processing android/support/v7/view/menu/ActionMenuItem.class...
processing android/support/v7/view/menu/ActionMenuItemView.class...
processing android/support/v7/view/menu/ActionMenuItemView$ActionMenuItemForwardingListener.class...
processing android/support/v7/view/menu/ActionMenuItemView$PopupCallback.class...
processing android/support/v7/view/menu/BaseMenuPresenter.class...
processing android/support/v7/view/menu/BaseMenuWrapper.class...
processing android/support/v7/view/menu/BaseWrapper.class...
processing android/support/v7/view/menu/ExpandedMenuView.class...
processing android/support/v7/view/menu/ListMenuItemView.class...
processing android/support/v7/view/menu/ListMenuPresenter.class...
processing android/support/v7/view/menu/ListMenuPresenter$MenuAdapter.class...
processing android/support/v7/view/menu/MenuBuilder.class...
processing android/support/v7/view/menu/MenuBuilder$Callback.class...
processing android/support/v7/view/menu/MenuBuilder$ItemInvoker.class...
processing android/support/v7/view/menu/MenuDialogHelper.class...
processing android/support/v7/view/menu/MenuItemImpl.class...
processing android/support/v7/view/menu/MenuItemImpl$1.class...
processing android/support/v7/view/menu/MenuItemWrapperICS.class...
processing android/support/v7/view/menu/MenuItemWrapperICS$ActionProviderWrapper.class...
processing android/support/v7/view/menu/MenuItemWrapperICS$CollapsibleActionViewWrapper.class...
processing android/support/v7/view/menu/MenuItemWrapperICS$OnActionExpandListenerWrapper.class...
processing android/support/v7/view/menu/MenuItemWrapperICS$OnMenuItemClickListenerWrapper.class...
processing android/support/v7/view/menu/MenuItemWrapperJB.class...
processing android/support/v7/view/menu/MenuItemWrapperJB$ActionProviderWrapperJB.class...
processing android/support/v7/view/menu/MenuPopupHelper.class...
processing android/support/v7/view/menu/MenuPopupHelper$MenuAdapter.class...
processing android/support/v7/view/menu/MenuPresenter.class...
processing android/support/v7/view/menu/MenuPresenter$Callback.class...
processing android/support/v7/view/menu/MenuView.class...
processing android/support/v7/view/menu/MenuView$ItemView.class...
processing android/support/v7/view/menu/MenuWrapperFactory.class...
processing android/support/v7/view/menu/MenuWrapperICS.class...
processing android/support/v7/view/menu/SubMenuBuilder.class...
processing android/support/v7/view/menu/SubMenuWrapperICS.class...
ignored resource android/support/v7/widget/
processing android/support/v7/widget/AbsActionBarView.class...
processing android/support/v7/widget/AbsActionBarView$1.class...
processing android/support/v7/widget/AbsActionBarView$VisibilityAnimListener.class...
processing android/support/v7/widget/ActionBarBackgroundDrawable.class...
processing android/support/v7/widget/ActionBarBackgroundDrawableV21.class...
processing android/support/v7/widget/ActionBarContainer.class...
processing android/support/v7/widget/ActionBarContextView.class...
processing android/support/v7/widget/ActionBarContextView$1.class...
processing android/support/v7/widget/ActionBarOverlayLayout.class...
processing android/support/v7/widget/ActionBarOverlayLayout$1.class...
processing android/support/v7/widget/ActionBarOverlayLayout$2.class...
processing android/support/v7/widget/ActionBarOverlayLayout$3.class...
processing android/support/v7/widget/ActionBarOverlayLayout$ActionBarVisibilityCallback.class...
processing android/support/v7/widget/ActionBarOverlayLayout$LayoutParams.class...
processing android/support/v7/widget/ActionMenuPresenter.class...
processing android/support/v7/widget/ActionMenuPresenter$1.class...
processing android/support/v7/widget/ActionMenuPresenter$ActionButtonSubmenu.class...
processing android/support/v7/widget/ActionMenuPresenter$ActionMenuPopupCallback.class...
processing android/support/v7/widget/ActionMenuPresenter$OpenOverflowRunnable.class...
processing android/support/v7/widget/ActionMenuPresenter$OverflowMenuButton.class...
processing android/support/v7/widget/ActionMenuPresenter$OverflowMenuButton$1.class...
processing android/support/v7/widget/ActionMenuPresenter$OverflowPopup.class...
processing android/support/v7/widget/ActionMenuPresenter$PopupPresenterCallback.class...
processing android/support/v7/widget/ActionMenuPresenter$SavedState.class...
processing android/support/v7/widget/ActionMenuPresenter$SavedState$1.class...
processing android/support/v7/widget/ActionMenuView.class...
processing android/support/v7/widget/ActionMenuView$1.class...
processing android/support/v7/widget/ActionMenuView$ActionMenuChildView.class...
processing android/support/v7/widget/ActionMenuView$ActionMenuPresenterCallback.class...
processing android/support/v7/widget/ActionMenuView$LayoutParams.class..<message truncated>


Please help me..
what i am doing wrong..
Thanks