Google AdMob Unable to convert classes into dex format

Im getting the following error when i try to build my project for android. I know this question has been asked a couple of times but i still can't seem to fix the issue. I recently implemented google admob into my project and this error has been popping up ever since i. I do not have any other plugins in the project (eg. facebook sdk etc.) I would really appreciate some help!

 CommandInvokationFailure: Unable to convert classes into dex format.
 C:/Program Files (x86)/Java/jdk1.8.0_101\bin\java.exe -Xmx1024M -Dcom.android.sdkmanager.toolsdir="D:/Android/android-sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -
 
 stderr[
 
 PARSE ERROR:
 unsupported class file version 52.0
 ...while parsing bitter/jnibridge/JNIBridge.class
 1 error; aborting
 ]
 stdout[
 processing archive D:\Unity\Projects\Unnamed shape game\Temp\StagingArea\android-libraries\android.arch.lifecycle.runtime-1.0.0\libs\.\classes.jar...
 processing android/arch/lifecycle/BuildConfig.class...
 processing android/arch/lifecycle/LifecycleRegistry.class...
 processing android/arch/lifecycle/LifecycleRegistry$1.class...
 processing android/arch/lifecycle/LifecycleRegistry$ObserverWithState.class...
 processing android/arch/lifecycle/LifecycleRegistryOwner.class...
 processing android/arch/lifecycle/ReportFragment.class...
 processing android/arch/lifecycle/ReportFragment$ActivityInitializationListener.class...
 processing archive D:\Unity\Projects\Unnamed shape game\Temp\StagingArea\android-libraries\com.android.support.customtabs-26.1.0\libs\.\classes.jar...
 processing android/support/customtabs/BuildConfig.class...
 processing android/support/customtabs/CustomTabsCallback.class...
 processing android/support/customtabs/CustomTabsClient.class...
 processing android/support/customtabs/CustomTabsClient$1.class...
 processing android/support/customtabs/CustomTabsClient$2.class...
 processing android/support/customtabs/CustomTabsClient$2$1.class...
 processing android/support/customtabs/CustomTabsClient$2$2.class...
 processing android/support/customtabs/CustomTabsClient$2$3.class...
 processing android/support/customtabs/CustomTabsClient$2$4.class...
 processing android/support/customtabs/CustomTabsIntent.class...
 processing android/support/customtabs/CustomTabsIntent$1.class...
 processing android/support/customtabs/CustomTabsIntent$Builder.class...
 processing android/support/customtabs/CustomTabsService.class...
 processing android/support/customtabs/CustomTabsService$1.class...
 processing android/support/customtabs/CustomTabsService$1$1.class...
 processing android/support/customtabs/CustomTabsService$Result.class...
 processing android/support/customtabs/CustomTabsServiceConnection.class...
 processing android/support/customtabs/CustomTabsServiceConnection$1.class...
 processing android/support/customtabs/CustomTabsSession.class...
 processing android/support/customtabs/CustomTabsSessionToken.class...
 processing android/support/customtabs/CustomTabsSessionToken$1.class...
 processing android/support/customtabs/ICustomTabsCallback.class...
 processing android/support/customtabs/ICustomTabsCallback$Stub.class...
 processing android/support/customtabs/ICustomTabsCallback$Stub$Proxy.class...
 processing android/support/customtabs/ICustomTabsService.class...
 processing android/support/customtabs/ICustomTabsService$Stub.class...
 processing android/support/customtabs/ICustomTabsService$Stub$Proxy.class...
 processing android/support/customtabs/IPostMessageService.class...
 processing android/support/customtabs/IPostMessageService$Stub.class...
 processing android/support/customtabs/IPostMessageService$Stub$Proxy.class...
 processing android/support/customtabs/PostMessageService.class...
 processing android/support/customtabs/PostMessageService$1.class...
 processing android/support/customtabs/PostMessageServiceConnection.class...
 processing archive D:\Unity\Projects\Unnamed shape game\Temp\StagingArea\android-libraries\com.android.support.support-compat-26.1.0\libs\.\classes.jar...
 processing android/support/compat/BuildConfig.class...
 processing android/support/v4/accessibilityservice/AccessibilityServiceInfoCompat.class...
 processing android/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoApi16Impl.class...
 processing android/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoApi18Impl.class...
 processing android/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoBaseImpl.class...
 processing android/support/v4/app/ActivityCompat.class...
 processing android/support/v4/app/ActivityCompat$1.class...
 processing android/support/v4/app/ActivityCompat$OnRequestPermissionsResultCallback.class...
 processing android/support/v4/app/ActivityCompat$RequestPermissionsRequestCodeValidator.class...
 processing android/support/v4/app/ActivityCompat$SharedElementCallback21Impl.class...
 processing android/support/v4/app/ActivityCompat$SharedElementCallback23Impl.class...
 processing android/support/v4/app/ActivityCompat$SharedElementCallback23Impl$1.class...
 processing android/support/v4/app/ActivityManagerCompat.class...
 processing android/support/v4/app/ActivityOptionsCompat.class...
 processing android/support/v4/app/ActivityOptionsCompat$ActivityOptionsCompatApi16Impl.class...
 processing android/support/v4/app/ActivityOptionsCompat$ActivityOptionsCompatApi23Impl.class...
 processing android/support/v4/app/ActivityOptionsCompat$ActivityOptionsCompatApi24Impl.class...
 processing android/support/v4/app/AlarmManagerCompat.class...
 processing android/support/v4/app/AppOpsManagerCompat.class...
 processing android/support/v4/app/BundleCompat.class...
 processing android/support/v4/app/BundleCompat$BundleCompatBaseImpl.class...
 processing android/support/v4/app/BundleUtil.class...
 processing android/support/v4/app/INotificationSideChannel.class...
 processing android/support/v4/app/INotificationSideChannel$Stub.class...
 processing android/support/v4/app/INotificationSideChannel$Stub$Proxy.class...
 processing android/support/v4/app/JobIntentService.class...
 processing android/support/v4/app/JobIntentService$CommandProcessor.class...
 processing android/support/v4/app/JobIntentService$CompatJobEngine.class...
 processing android/support/v4/app/JobIntentService$CompatWorkEnqueuer.class...
 processing android/support/v4/app/JobIntentService$CompatWorkItem.class...
 processing android/support/v4/app/JobIntentService$GenericWorkItem.class...
 processing android/support/v4/app/JobIntentService$JobServiceEngineImpl.class...
 processing android/support/v4/app/JobIntentService$JobServiceEngineImpl$WrapperWorkItem.class...
 processing android/support/v4/app/JobIntentService$JobWorkEnqueuer.class...
 processing android/support/v4/app/JobIntentService$WorkEnqueuer.class...
 processing android/support/v4/app/NotificationBuilderWithActions.class...
 processing android/support/v4/app/NotificationBuilderWithBuilderAccessor.class...
 processing android/support/v4/app/NotificationCompat.class...
 processing android/support/v4/app/NotificationCompat$Action.class...
 processing android/support/v4/app/NotificationCompat$Action$1.class...
 processing android/support/v4/app/NotificationCompat$Action$Builder.class...
 processing android/support/v4/app/NotificationCompat$Action$Extender.class...
 processing android/support/v4/app/NotificationCompat$Action$WearableExtender.class...
 processing android/support/v4/app/NotificationCompat$BadgeIconType.class...
 processing android/support/v4/app/NotificationCompat$BigPictureStyle.class...
 processing android/support/v4/app/NotificationCompat$BigTextStyle.class...
 processing android/support/v4/app/NotificationCompat$Builder.class...
 processing android/support/v4/app/NotificationCompat$BuilderExtender.class...
 processing android/support/v4/app/NotificationCompat$CarExtender.class...
 processing android/support/v4/app/NotificationCompat$CarExtender$UnreadConversation.class...
 processing android/support/v4/app/NotificationCompat$CarExtender$UnreadConversation$1.class...
 processing android/support/v4/app/NotificationCompat$CarExtender$UnreadConversation$Builder.class...
 processing android/support/v4/app/NotificationCompat$DecoratedCustomViewStyle.class...
 processing android/support/v4/app/NotificationCompat$Extender.class...
 processing android/support/v4/app/NotificationCompat$InboxStyle.class...
 processing android/support/v4/app/NotificationCompat$MessagingStyle.class...
 processing android/support/v4/app/NotificationCompat$MessagingStyle$Message.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatApi16Impl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatApi19Impl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatApi20Impl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatApi21Impl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatApi24Impl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatApi26Impl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatBaseImpl.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatBaseImpl$BuilderBase.class...
 processing android/support/v4/app/NotificationCompat$NotificationCompatImpl.class...
 processing android/support/v4/app/NotificationCompat$NotificationVisibility.class...
 processing android/support/v4/app/NotificationCompat$Style.class...
 processing android/support/v4/app/NotificationCompat$WearableExtender.class...
 processing android/support/v4/app/NotificationCompatApi20.class...
 processing android/support/v4/app/NotificationCompatApi20$Builder.class...
 processing android/support/v4/app/NotificationCompatApi21.class...
 processing android/support/v4/app/NotificationCompatApi21$Builder.class...
 processing android/support/v4/app/NotificationCompatApi24.class...
 processing android/support/v4/app/NotificationCompatApi24$Builder.class...
 processing android/support/v4/app/NotificationCompatApi26.class...
 processing android/support/v4/app/NotificationCompatApi26$Builder.class...
 processing android/support/v4/app/NotificationCompatBase.class...
 processing android/support/v4/app/NotificationCompatBase$Action.class...
 processing android/support/v4/app/NotificationCompatBase$Action$Factory.class...
 processing android/support/v4/app/NotificationCompatBase$UnreadConversation.class...
 processing android/support/v4/app/NotificationCompatBase$UnreadConversation$Factory.class...
 processing android/support/v4/app/NotificationCompatExtras.class...
 processing android/support/v4/app/NotificationCompatJellybean.class...
 processing android/support/v4/app/NotificationCompatJellybean$Builder.class...
 processing android/support/v4/app/NotificationCompatKitKat.class...
 processing android/support/v4/app/NotificationCompatKitKat$Builder.class...
 processing android/support/v4/app/NotificationCompatSideChannelService.class...
 processing android/support/v4/app/NotificationCompatSideChannelService$NotificationSideChannelStub.class...
 processing android/support/v4/app/NotificationManagerCompat.class...
 processing android/support/v4/app/NotificationManagerCompat$CancelTask.class...
 processing android/support/v4/app/NotificationManagerCompat$NotifyTask.class...
 processing android/support/v4/app/NotificationManagerCompat$ServiceConnectedEvent.class...
 processing android/support/v4/app/NotificationManagerCompat$SideChannelManager.class...
 processing android/support/v4/app/NotificationManagerCompat$SideChannelManager$ListenerRecord.class...
 processing android/support/v4/app/NotificationManagerCompat$Task.class...
 processing android/support/v4/app/RemoteInput.class...
 processing android/support/v4/app/RemoteInput$1.class...
 processing android/support/v4/app/RemoteInput$Builder.class...
 processing android/support/v4/app/RemoteInput$Impl.class...
 processing android/support/v4/app/RemoteInput$ImplApi20.class...
 processing android/support/v4/app/RemoteInput$ImplBase.class...
 processing android/support/v4/app/RemoteInput$ImplJellybean.class...
 processing android/support/v4/app/RemoteInputCompatApi20.class...
 processing android/support/v4/app/RemoteInputCompatBase.class...
 processing android/support/v4/app/RemoteInputCompatBase$RemoteInput.class...
 processing android/support/v4/app/RemoteInputCompatBase$RemoteInput$Factory.class...
 processing android/support/v4/app/RemoteInputCompatJellybean.class...
 processing android/support/v4/app/ServiceCompat.class...
 processing android/support/v4/app/ServiceCompat$StopForegroundFlags.class...
 processing android/support/v4/app/ShareCompat.class...
 processing android/support/v4/app/ShareCompat$IntentBuilder.class...
 processing android/support/v4/app/ShareCompat$IntentReader.class...
 processing android/support/v4/app/SharedElementCallback.class...
 processing android/support/v4/app/SharedElementCallback$OnSharedElementsReadyListener.class...
 processing android/support/v4/app/SupportActivity.class...
 processing android/support/v4/app/SupportActivity$ExtraData.class...
 processing android/support/v4/content/ContentResolverCompat.class...
 processing android/support/v4/content/ContextCompat.class...
 processing android/support/v4/content/IntentCompat.class...
 processing android/support/v4/content/IntentCompat$IntentCompatApi15Impl.class...
 processing android/support/v4/content/IntentCompat$IntentCompatBaseImpl.class...
 processing android/support/v4/content/ModernAsyncTask.class...
 processing android/support/v4/content/ModernAsyncTask$1.class...
 processing android/support/v4/content/ModernAsyncTask$2.class...
 processing android/support/v4/content/ModernAsyncTask$3.class...
 processing android/support/v4/content/ModernAsyncTask$4.class...
 processing android/support/v4/content/ModernAsyncTask$AsyncTaskResult.class...
 processing android/support/v4/content/ModernAsyncTask$InternalHandler.class...
 processing android/support/v4/content/ModernAsyncTask$Status.class...
 processing android/support/v4/content/ModernAsyncTask$WorkerRunnable.class...
 processing android/support/v4/content/ParallelExecutorCompat.class...
 processing android/support/v4/content/SharedPreferencesCompat.class...
 processing android/support/v4/content/SharedPreferencesCompat$EditorCompat.class...
 processing android/support/v4/content/SharedPreferencesCompat$EditorCompat$Helper.class...
 processing android/support/v4/content/pm/ActivityInfoCompat.class...
 processing android/support/v4/content/pm/ShortcutInfoCompat.class...
 processing android/support/v4/content/pm/ShortcutInfoCompat$1.class...
 processing android/support/v4/content/pm/ShortcutInfoCompat$Builder.class...
 processing android/support/v4/content/pm/ShortcutManagerCompat.class...
 processing android/support/v4/content/pm/ShortcutManagerCompat$1.class...
 processing android/support/v4/content/res/ConfigurationHelper.class...
 processing android/support/v4/content/res/FontResourcesParserCompat.class...
 processing android/support/v4/content/res/FontResourcesParserCompat$FamilyResourceEntry.class...
 processing android/support/v4/content/res/FontResourcesParserCompat$FetchStrategy.class...
 processing android/support/v4/content/res/FontResourcesParserCompat$FontFamilyFilesResourceEntry.class...
 processing android/support/v4/content/res/FontResourcesParserCompat$FontFileResourceEntry.class...
 processing android/support/v4/content/res/FontResourcesParserCompat$ProviderResourceEntry.class...
 processing android/support/v4/content/res/ResourcesCompat.class...
 processing android/support/v4/content/res/TypedArrayUtils.class...
 processing android/support/v4/database/DatabaseUtilsCompat.class...
 processing android/support/v4/graphics/BitmapCompat.class...
 processing android/support/v4/graphics/BitmapCompat$BitmapCompatApi18Impl.class...
 processing android/support/v4/graphics/BitmapCompat$BitmapCompatApi19Impl.class...
 processing android/support/v4/graphics/BitmapCompat$BitmapCompatBaseImpl.class...
 processing android/support/v4/graphics/PaintCompat.class...
 processing android/support/v4/graphics/PaintCompatApi14.class...
 processing android/support/v4/graphics/PathParser.class...
 processing android/support/v4/graphics/PathParser$ExtractFloatResult.class...
 processing android/support/v4/graphics/PathParser$PathDataNode.class...
 processing android/support/v4/graphics/TypefaceCompat.class...
 processing android/support/v4/graphics/TypefaceCompat$TypefaceCompatImpl.class...
 processing android/support/v4/graphics/TypefaceCompatApi21Impl.class...
 processing android/support/v4/graphics/TypefaceCompatApi24Impl.class...
 processing android/support/v4/graphic<message truncated>