Unable to convert classes into dex format NO FILES DOUBLE!

I am so mad about this. I need to update a project I long had finished for the Google Play Store because it got kicked after years of being online for a minor reason. So I am loading the old files back up, everything seems to work - I can play the game in the editor. Then I want to render the .apk and unity fails first by saying:

“SDK Build Tools version 25.0.3 < 28.0.3.” I can either say “Update Android SDK” but this fails or just click “Use Highest Installed” which I always did for my other project and it worked.

After I have done this is gets until the point where it is converting the classes into dex. It fails with a LONG message (seen below).

I read through countless articles all stating that I probably have a class twice. Some had Google Ads and Facebook SDK integerated and both included the android-support-v4 library. They deleted one of the two and that did the trick. But I dont have facebook integrated. I do however have GoogleMobileAds integrated.

So I checked my folder containing my project and search for .jar or .aar files and I had quite a few doublicates. I deleted them all and still get the same error. I have also noticed, that some files keep reoccuring after one build.

Sometimes, after deleteing them again, I return to Unity and it starts some “Resolving Android Dependencies” window that then also just “fails” and I return to where I was.

This is absolutley terrible. All my current projects work JUSt fine but the one I need to update failes. Here is the log:

CommandInvokationFailure: Unable to convert classes into dex format.
D:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\OpenJDK\Windows\bin\java.exe -Xmx8000M -Dcom.android.sdkmanager.toolsdir=“C:/Program Files (x86)/Android/android-sdk\tools” -Dfile.encoding=UTF8 -jar “D:\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:\Big Projects\Games\Guess The Sheet\UnityProjekt\GuessTheSheet\Temp\StagingArea\android-libraries\GoogleAIDL\libs.\classes.jar…
processing com/android/vending/billing/BuildConfig.class…
processing com/android/vending/billing/IInAppBillingService.class…
processing com/android/vending/billing/IInAppBillingService$Stub.class…
processing com/android/vending/billing/IInAppBillingService$Stub$Proxy.class…
processing archive D:\Big Projects\Games\Guess The Sheet\UnityProjekt\GuessTheSheet\Temp\StagingArea\android-libraries\GoogleMobileAdsPlugin\libs.\unity-plugin-library.jar…
processing com/google/unity/BuildConfig.class…
processing com/google/unity/ads/AdNetworkExtras.class…
processing com/google/unity/ads/Banner.class…
processing com/google/unity/ads/Banner$1.class…
processing com/google/unity/ads/Banner$2.class…
processing com/google/unity/ads/Banner$3.class…
processing com/google/unity/ads/Banner$4.class…
processing com/google/unity/ads/Banner$5.class…
processing com/google/unity/ads/Banner$6.class…
processing com/google/unity/ads/Banner$7.class…
processing com/google/unity/ads/CustomNativeAd.class…
processing com/google/unity/ads/CustomNativeAd$1.class…
processing com/google/unity/ads/CustomNativeAd$2.class…
processing com/google/unity/ads/Interstitial.class…
processing com/google/unity/ads/Interstitial$1.class…
processing com/google/unity/ads/Interstitial$1$1.class…
processing com/google/unity/ads/Interstitial$2.class…
processing com/google/unity/ads/Interstitial$3.class…
processing com/google/unity/ads/NativeAdLoader.class…
processing com/google/unity/ads/NativeAdLoader$1.class…
processing com/google/unity/ads/NativeAdLoader$2.class…
processing com/google/unity/ads/NativeAdLoader$3.class…
processing com/google/unity/ads/NativeAdLoader$3$1.class…
processing com/google/unity/ads/NativeAdLoader$3$2.class…
processing com/google/unity/ads/NativeAdLoader$3$3.class…
processing com/google/unity/ads/NativeAdLoader$4.class…
processing com/google/unity/ads/NativeExpressAd.class…
processing com/google/unity/ads/NativeExpressAd$1.class…
processing com/google/unity/ads/NativeExpressAd$2.class…
processing com/google/unity/ads/NativeExpressAd$3.class…
processing com/google/unity/ads/NativeExpressAd$4.class…
processing com/google/unity/ads/NativeExpressAd$5.class…
processing com/google/unity/ads/NativeExpressAd$6.class…
processing com/google/unity/ads/NativeExpressAd$7.class…
processing com/google/unity/ads/NativeExpressAd$8.class…
processing com/google/unity/ads/PluginUtils.class…
processing com/google/unity/ads/RewardBasedVideo.class…
processing com/google/unity/ads/RewardBasedVideo$1.class…
processing com/google/unity/ads/RewardBasedVideo$1$1.class…
processing com/google/unity/ads/RewardBasedVideo$2.class…
processing com/google/unity/ads/RewardBasedVideo$3.class…
processing com/google/unity/ads/UnityAdListener.class…
processing com/google/unity/ads/UnityAdLoaderListener.class…
processing com/google/unity/ads/UnityRewardBasedVideoAdListener.class…
processing archive D:\Big Projects\Games\Guess The Sheet\UnityProjekt\GuessTheSheet\Temp\StagingArea\android-libraries\GooglePlay\libs.\classes.jar…
processing com/unity/purchasing/googleplay/ActivityLauncher.class…
processing com/unity/purchasing/googleplay/BillingServiceManager.class…
processing com/unity/purchasing/googleplay/BillingServiceManager$1.class…
processing com/unity/purchasing/googleplay/BillingServiceManager$1$1.class…
processing com/unity/purchasing/googleplay/BillingServiceManager$1$2.class…
processing com/unity/purchasing/googleplay/BillingServiceManager$2.class…
processing com/unity/purchasing/googleplay/BillingServiceProcessor.class…
processing com/unity/purchasing/googleplay/BuildConfig.class…
processing com/unity/purchasing/googleplay/Consts.class…
processing com/unity/purchasing/googleplay/Consts$PurchaseState.class…
processing com/unity/purchasing/googleplay/Consts$ResponseCode.class…
processing com/unity/purchasing/googleplay/GooglePlayBillingUnAvailableException.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$1.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$2.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$3.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$4.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$5.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$6.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$7.class…
processing com/unity/purchasing/googleplay/GooglePlayPurchasing$Features.class…
processing com/unity/purchasing/googleplay/IActivityLauncher.class…
processing com/unity/purchasing/googleplay/IBillingServiceManager.class…
processing com/unity/purchasing/googleplay/IabException.class…
processing com/unity/purchasing/googleplay/IabHelper.class…
processing com/unity/purchasing/googleplay/IabHelper$1.class…
processing com/unity/purchasing/googleplay/IabHelper$2.class…
processing com/unity/purchasing/googleplay/IabHelper$2$1.class…
processing com/unity/purchasing/googleplay/IabHelper$3.class…
processing com/unity/purchasing/googleplay/IabHelper$4.class…
processing com/unity/purchasing/googleplay/IabHelper$OnConsumeFinishedListener.class…
processing com/unity/purchasing/googleplay/IabHelper$OnConsumeMultiFinishedListener.class…
processing com/unity/purchasing/googleplay/IabHelper$OnIabPurchaseFinishedListener.class…
processing com/unity/purchasing/googleplay/IabHelper$OnIabSetupFinishedListener.class…
processing com/unity/purchasing/googleplay/IabHelper$QueryInventoryFinishedListener.class…
processing com/unity/purchasing/googleplay/IabResult.class…
processing com/unity/purchasing/googleplay/Inventory.class…
processing com/unity/purchasing/googleplay/Purchase.class…
processing com/unity/purchasing/googleplay/PurchaseActivity.class…
processing com/unity/purchasing/googleplay/PurchaseFailedEvent.class…
processing com/unity/purchasing/googleplay/SkuDetails.class…
processing com/unity/purchasing/googleplay/VRPurchaseActivity.class…
processing archive D:\Big Projects\Games\Guess The Sheet\UnityProjekt\GuessTheSheet\Temp\StagingArea\android-libraries\UnityAds\libs.\classes.jar…
processing com/unity3d/ads/BuildConfig.class…
processing com/unity3d/ads/IUnityAdsListener.class…
processing com/unity3d/ads/UnityAds.class…
processing com/unity3d/ads/UnityAds$1.class…
processing com/unity3d/ads/UnityAds$2.class…
processing com/unity3d/ads/UnityAds$FinishState.class…
processing com/unity3d/ads/UnityAds$PlacementState.class…
processing com/unity3d/ads/UnityAds$UnityAdsError.class…
processing com/unity3d/ads/adunit/AdUnitActivity.class…
processing com/unity3d/ads/adunit/AdUnitError.class…
processing com/unity3d/ads/adunit/AdUnitEvent.class…
processing com/unity3d/ads/adunit/AdUnitOpen.class…
processing com/unity3d/ads/adunit/AdUnitSoftwareActivity.class…
processing com/unity3d/ads/adunit/AdUnitTransparentActivity.class…
processing com/unity3d/ads/adunit/AdUnitTransparentSoftwareActivity.class…
processing com/unity3d/ads/api/AdUnit.class…
processing com/unity3d/ads/api/AdUnit$1.class…
processing com/unity3d/ads/api/AdUnit$2.class…
processing com/unity3d/ads/api/AdUnit$3.class…
processing com/unity3d/ads/api/AdUnit$4.class…
processing com/unity3d/ads/api/AdUnit$5.class…
processing com/unity3d/ads/api/Broadcast.class…
processing com/unity3d/ads/api/Cache.class…
processing com/unity3d/ads/api/Cache$1.class…
processing com/unity3d/ads/api/Connectivity.class…
processing com/unity3d/ads/api/DeviceInfo.class…
processing com/unity3d/ads/api/DeviceInfo$1.class…
processing com/unity3d/ads/api/DeviceInfo$2.class…
processing com/unity3d/ads/api/DeviceInfo$DeviceInfoEvent.class…
processing com/unity3d/ads/api/DeviceInfo$StorageType.class…
processing com/unity3d/ads/api/Intent.class…
processing com/unity3d/ads/api/Intent$IntentError.class…
processing com/unity3d/ads/api/Lifecycle.class…
processing com/unity3d/ads/api/Listener.class…
processing com/unity3d/ads/api/Listener$1.class…
processing com/unity3d/ads/api/Listener$2.class…
processing com/unity3d/ads/api/Listener$3.class…
processing com/unity3d/ads/api/Listener$4.class…
processing com/unity3d/ads/api/Listener$5.class…
processing com/unity3d/ads/api/Listener$6.class…
processing com/unity3d/ads/api/Listener$7.class…
processing com/unity3d/ads/api/Placement.class…
processing com/unity3d/ads/api/Request.class…
processing com/unity3d/ads/api/Request$1.class…
processing com/unity3d/ads/api/Request$2.class…
processing com/unity3d/ads/api/Request$3.class…
processing com/unity3d/ads/api/Resolve.class…
processing com/unity3d/ads/api/Resolve$1.class…
processing com/unity3d/ads/api/Sdk.class…
processing com/unity3d/ads/api/Storage.class…
processing com/unity3d/ads/api/VideoPlayer.class…
processing com/unity3d/ads/api/VideoPlayer$1.class…
processing com/unity3d/ads/api/VideoPlayer$2.class…
processing com/unity3d/ads/api/VideoPlayer$3.class…
processing com/unity3d/ads/api/VideoPlayer$4.class…
processing com/unity3d/ads/api/VideoPlayer$5.class…
processing com/unity3d/ads/api/VideoPlayer$6.class…
processing com/unity3d/ads/broadcast/BroadcastError.class…
processing com/unity3d/ads/broadcast/BroadcastEvent.class…
processing com/unity3d/ads/broadcast/BroadcastEventReceiver.class…
processing com/unity3d/ads/broadcast/BroadcastMonitor.class…
processing com/unity3d/ads/cache/CacheDirectory.class…
processing com/unity3d/ads/cache/CacheError.class…
processing com/unity3d/ads/cache/CacheEvent.class…
processing com/unity3d/ads/cache/CacheThread.class…
processing com/unity3d/ads/cache/CacheThreadHandler.class…
processing com/unity3d/ads/cache/CacheThreadHandler$1.class…
processing com/unity3d/ads/configuration/Configuration.class…
processing com/unity3d/ads/configuration/ConfigurationFailure.class…
processing com/unity3d/ads/configuration/EnvironmentCheck.class…
processing com/unity3d/ads/configuration/InitializeThread.class…
processing com/unity3d/ads/configuration/InitializeThread$1.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeState.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateAdBlockerCheck.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateAdBlockerCheck$1.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateAdBlockerCheck$2.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateComplete.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateConfig.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateCreate.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateError.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateError$1.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateLoadCache.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateLoadWeb.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateNetworkError.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateReset.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateReset$1.class…
processing com/unity3d/ads/configuration/InitializeThread$InitializeStateRetry.class…
processing com/unity3d/ads/connectivity/ConnectivityChangeReceiver.class…
processing com/unity3d/ads/connectivity/ConnectivityEvent.class…
processing com/unity3d/ads/connectivity/ConnectivityMonitor.class…
processing com/unity3d/ads/connectivity/ConnectivityMonitor$1.class…
processing com/unity3d/ads/connectivity/ConnectivityNetworkCallback.class…
processing com/unity3d/ads/connectivity/IConnectivityListener.class…
processing com/unity3d/ads/device/AdvertisingId.class…
processing com/unity3d/ads/device/AdvertisingId$1.class…
processing com/unity3d/ads/device/AdvertisingId$GoogleAdvertisingInfo.class…
processing com/unity3d/ads/device/AdvertisingId$GoogleAdvertisingInfo$GoogleAdvertisingInfoBinder.class…
processing com/unity3d/ads/device/AdvertisingId$GoogleAdvertisingInfo$GoogleAdvertisingInfoBinder$GoogleAdvertisingInfoImplementation.class…
processing com/unity3d/ads/device/AdvertisingId$GoogleAdvertisingServiceConnection.class…
processing com/unity3d/ads/device/Device.class…
processing com/unity3d/ads/device/Device$1.class…
processing com/unity3d/ads/device/Device$MemoryInfoType.class…
processing com/unity3d/ads/device/DeviceError.class…
processing com/unity3d/ads/device/IVolumeChangeListener.class…
processing com/unity3d/ads/device/Storage.class…
processing com/unity3d/ads/device/StorageError.class…
processing com/unity3d/ads/device/StorageEvent.class…
processing com/unity3d/ads/device/StorageManager.class…
processing com/unity3d/ads/device/StorageManager$StorageType.class…
processing com/unity3d/ads/device/VolumeChange.class…
processing com/unity3d/ads/device/VolumeChange$1.class…
processing com/unity3d/ads/lifecycle/LifecycleError.class…
processing com/unity3d/ads/lifecycle/LifecycleEvent.class…
processing com/unity3d/ads/lifecycle/LifecycleListener.class…
processing com/unity3d/ads/log/DeviceLog.class…
processing com/unity3d/ads/log/DeviceLog$1.class…
processing com/unity3d/ads/log/DeviceLog$UnityAdsLogLevel.class…
processing com/unity3d/ads/log/DeviceLogEntry.class…
processing com/unity3d/ads/log/DeviceLogLevel.class…
processing com/unity3d/ads/mediation/IUnityAdsExtendedListener.class…
processing com/unity3d/ads/metadata/InAppPurchaseMetaData.class…
processing com/unity3d/ads/metadata/MediationMetaData.class…
processing com/unity3d/ads/metadata/MetaData.class…
processing com/unity3d/ads/metadata/PlayerMetaData.class…
processing com/unity3d/ads/misc/JsonStorage.class…
processing com/unity3d/ads/misc/Utilities.class…
processing com/unity3d/ads/misc/ViewUtilities.class…
processing com/unity3d/ads/placement/Placement.class…
processing com/unity3d/ads/properties/ClientProperties.class…
processing com/unity3d/ads/properties/SdkProperties.class…
processing com/unity3d/ads/request/IResolveHostListener.class…
processing com/unity3d/ads/request/IWebRequestListener.class…
processing com/unity3d/ads/request/IWebRequestProgressListener.class…
processing com/unity3d/ads/request/NetworkIOException.class…
processing com/unity3d/ads/request/ResolveHostError.class…
processing com/unity3d/ads/request/ResolveHostEvent.class…
processing com/unity3d/ads/request/WebRequest.class…
processing com/unity3d/ads/request/WebRequest$RequestType.class…
processing com/unity3d/ads/request/WebRequestError.class…
processing com/unity3d/ads/request/WebRequestEvent.class…
processing com/unity3d/ads/request/WebRequestHandler.class…
processing com/unity3d/ads/request/WebRequestResultReceiver.class…
processing com/unity3d/ads/request/WebRequestThread.class…
processing com/unity3d/ads/request/WebRequestThread$1.class…
processing com/unity3d/ads/request/WebRequestThread$1$1.class…
processing com/unity3d/ads/unity/IUnityAdsUnityListener.class…
processing com/unity3d/ads/video/VideoPlayerError.class…
processing com/unity3d/ads/video/VideoPlayerEvent.class…
processing com/unity3d/ads/video/VideoPlayerView.class…
processing com/unity3d/ad

You might not be having Java 1.8 installed leading to a failure.
As per Java Specification,

Make sure you have libraries targeted with Java 1.8. You can simply update your libraries once and give a try and it should mostly resolve. Also, you need to have Java 1.8 installed.

Thank you for your answer. However, my other projects all run fine…

You should make sure you are using JDK 8