Unable to Convert classes into dex Format

got an error

CommandInvokationFailure: Unable to convert classes into dex format.
C:/Program Files/Java/jdk1.8.0_121\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:/Users/Tiwari/AppData/Local/Android/sdk	ools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -

stderr[
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/CampaignTrackingReceiver;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/CampaignTrackingService;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/CampaignTrackingService$1;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/CampaignTrackingService$2;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/CampaignTrackingService$3;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/ExceptionParser;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/ExceptionReporter;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/GoogleAnalytics;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/analytics/GoogleAnalytics$zza;

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.RuntimeException: Translation has been interrupted
	at com.android.dx.command.dexer.Main.processAllFiles(Main.java:613)
	at com.android.dx.command.dexer.Main.runMonoDex(Main.java:311)
	at com.android.dx.command.dexer.Main.run(Main.java:277)
	at com.android.dx.command.dexer.Main.main(Main.java:245)
	at com.android.dx.command.Main.main(Main.java:106)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at SDKMain.main(SDKMain.java:130)
Caused by: java.lang.InterruptedException: Too many errors
	at com.android.dx.command.dexer.Main.processAllFiles(Main.java:605)
	... 9 more
]
stdout[
processing archive H:\Game Projects Mega InfoMatix\Sniper 3D- City Apocalypse\Sniper 3D- City Apocalypse\sniper3D_projects\Sniper 3D Android\Temp\StagingArea\android-libraries\play-services-analytics-impl\libs\.\classes.jar...
ignored resource META-INF/
ignored resource META-INF/MANIFEST.MF
ignored resource com/
ignored resource com/google/
ignored resource com/google/android/
ignored resource com/google/android/gms/
ignored resource com/google/android/gms/analytics/
processing com/google/android/gms/analytics/CampaignTrackingReceiver.class...
processing com/google/android/gms/analytics/CampaignTrackingService.class...
processing com/google/android/gms/analytics/CampaignTrackingService$1.class...
processing com/google/android/gms/analytics/CampaignTrackingService$2.class...
processing com/google/android/gms/analytics/CampaignTrackingService$3.class...
processing com/google/android/gms/analytics/ExceptionParser.class...
processing com/google/android/gms/analytics/ExceptionReporter.class...
processing com/google/android/gms/analytics/GoogleAnalytics.class...
processing com/google/android/gms/analytics/GoogleAnalytics$zza.class...
processing com/google/android/gms/analytics/GoogleAnalytics$zzb.class...
processing com/google/android/gms/analytics/HitBuilders.class...
processing com/google/android/gms/analytics/HitBuilders$AppViewBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$EventBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$ExceptionBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$HitBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$ItemBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$ScreenViewBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$SocialBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$TimingBuilder.class...
processing com/google/android/gms/analytics/HitBuilders$TransactionBuilder.class...
processing com/google/android/gms/analytics/Logger.class...
processing com/google/android/gms/analytics/Logger$LogLevel.class...
processing com/google/android/gms/analytics/StandardExceptionParser.class...
processing com/google/android/gms/analytics/Tracker.class...
processing com/google/android/gms/analytics/Tracker$1.class...
processing com/google/android/gms/analytics/Tracker$zza.class...
ignored resource com/google/android/gms/analytics/ecommerce/
processing com/google/android/gms/analytics/ecommerce/Product.class...
processing com/google/android/gms/analytics/ecommerce/ProductAction.class...
processing com/google/android/gms/analytics/ecommerce/Promotion.class...
ignored resource com/google/android/gms/analytics/internal/
processing com/google/android/gms/analytics/internal/Command.class...
processing com/google/android/gms/analytics/internal/Command$1.class...
processing com/google/android/gms/analytics/internal/zza.class...
processing com/google/android/gms/analytics/internal/zzaa.class...
processing com/google/android/gms/analytics/internal/zzab.class...
processing com/google/android/gms/analytics/internal/zzac.class...
processing com/google/android/gms/analytics/internal/zzac$zza.class...
processing com/google/android/gms/analytics/internal/zzac$zza$zza.class...
processing com/google/android/gms/analytics/internal/zzad.class...
processing com/google/android/gms/analytics/internal/zzae.class...
processing com/google/android/gms/analytics/internal/zzaf.class...
processing com/google/android/gms/analytics/internal/zzag.class...
processing com/google/android/gms/analytics/internal/zzah.class...
processing com/google/android/gms/analytics/internal/zzah$zza.class...
processing com/google/android/gms/analytics/internal/zzai.class...
processing com/google/android/gms/analytics/internal/zzai$1.class...
processing com/google/android/gms/analytics/internal/zzai$zza.class...
processing com/google/android/gms/analytics/internal/zzaj.class...
processing com/google/android/gms/analytics/internal/zzak.class...
processing com/google/android/gms/analytics/internal/zzak$1.class...
processing com/google/android/gms/analytics/internal/zzak$1$1.class...
processing com/google/android/gms/analytics/internal/zzak$zza.class...
processing com/google/android/gms/analytics/internal/zzal.class...
processing com/google/android/gms/analytics/internal/zzam.class...
processing com/google/android/gms/analytics/internal/zzam$zza.class...
processing com/google/android/gms/analytics/internal/zzan.class...
processing com/google/android/gms/analytics/internal/zzao.class...
processing com/google/android/gms/analytics/internal/zzap.class...
processing com/google/android/gms/analytics/internal/zzb.class...
processing com/google/android/gms/analytics/internal/zzb$1.class...
processing com/google/android/gms/analytics/internal/zzb$2.class...
processing com/google/android/gms/analytics/internal/zzb$3.class...
processing com/google/android/gms/analytics/internal/zzb$4.class...
processing com/google/android/gms/analytics/internal/zzb$5.class...
processing com/google/android/gms/analytics/internal/zzb$6.class...
processing com/google/android/gms/analytics/internal/zzb$7.class...
processing com/google/android/gms/analytics/internal/zzc.class...
processing com/google/android/gms/analytics/internal/zzd.class...
processing com/google/android/gms/analytics/internal/zze.class...
processing com/google/android/gms/analytics/internal/zzf.class...
processing com/google/android/gms/analytics/internal/zzf$1.class...
processing com/google/android/gms/analytics/internal/zzg.class...
processing com/google/android/gms/analytics/internal/zzh.class...
processing com/google/android/gms/analytics/internal/zzi.class...
processing com/google/android/gms/analytics/internal/zzi$1.class...
processing com/google/android/gms/analytics/internal/zzi$zza.class...
processing com/google/android/gms/analytics/internal/zzi$zza$1.class...
processing com/google/android/gms/analytics/internal/zzi$zza$2.class...
processing com/google/android/gms/analytics/internal/zzj.class...
processing com/google/android/gms/analytics/internal/zzj$zza.class...
processing com/google/android/gms/analytics/internal/zzk.class...
processing com/google/android/gms/analytics/internal/zzl.class...
processing com/google/android/gms/analytics/internal/zzl$1.class...
processing com/google/android/gms/analytics/internal/zzl$2.class...
processing com/google/android/gms/analytics/internal/zzl$3.class...
processing com/google/android/gms/analytics/internal/zzl$4.class...
processing com/google/android/gms/analytics/internal/zzl$5.class...
processing com/google/android/gms/analytics/internal/zzm.class...
processing com/google/android/gms/analytics/internal/zzn.class...
processing com/google/android/gms/analytics/internal/zzn$1.class...
processing com/google/android/gms/analytics/internal/zzn$2.class...
processing com/google/android/gms/analytics/internal/zzo.class...
processing com/google/android/gms/analytics/internal/zzp.class...
processing com/google/android/gms/analytics/internal/zzq.class...
processing com/google/android/gms/analytics/internal/zzq$zza.class...
processing com/google/android/gms/analytics/internal/zzr.class...
processing com/google/android/gms/analytics/internal/zzs.class...
processing com/google/android/gms/analytics/internal/zzt.class...
processing com/google/android/gms/analytics/internal/zzt$1.class...
processing com/google/android/gms/analytics/internal/zzu.class...
processing com/google/android/gms/analytics/internal/zzv.class...
processing com/google/android/gms/analytics/internal/zzw.class...
processing com/google/android/gms/analytics/internal/zzx.class...
processing com/google/android/gms/analytics/internal/zzy.class...
processing com/google/android/gms/analytics/internal/zzy$zza.class...
processing com/google/android/gms/analytics/internal/zzz.class...
processing com/google/android/gms/analytics/internal/zzz$zza.class...
processing com/google/android/gms/analytics/zza.class...
processing com/google/android/gms/analytics/zzb.class...
processing com/google/android/gms/analytics/zzc.class...
processing com/google/android/gms/analytics/zzd.class...
processing com/google/android/gms/analytics/zzd$1.class...
processing com/google/android/gms/analytics/zze.class...
processing com/google/android/gms/analytics/zzf.class...
processing com/google/android/gms/analytics/zzg.class...
processing com/google/android/gms/analytics/zzh.class...
processing com/google/android/gms/analytics/zzi.class...
processing com/google/android/gms/analytics/zzi$1.class...
processing com/google/android/gms/analytics/zzi$zza.class...
processing com/google/android/gms/analytics/zzi$zza$1.class...
processing com/google/android/gms/analytics/zzi$zzb.class...
processing com/google/android/gms/analytics/zzi$zzc.class...
processing com/google/android/gms/analytics/zzj.class...
processing com/google/android/gms/analytics/zzk.class...
ignored resource com/google/android/gms/internal/
processing com/google/android/gms/internal/zzady.class...
processing com/google/android/gms/internal/zzadz.class...
processing com/google/android/gms/internal/zzadz$1.class...
processing com/google/android/gms/internal/zzadz$zza.class...
processing com/google/android/gms/internal/zzadz$zzb.class...
processing com/google/android/gms/internal/zzadz$zzc.class...
processing com/google/android/gms/internal/zzadz$zzd.class...
processing com/google/android/gms/internal/zzadz$zze.class...
processing com/google/android/gms/internal/zzadz$zzf.class...
processing com/google/android/gms/internal/zzadz$zzg.class...
processing com/google/android/gms/internal/zzaea.class...
processing com/google/android/gms/internal/zzaeb.class...
processing com/google/android/gms/internal/zzaec.class...
processing com/google/android/gms/internal/zzaed.class...
processing com/google/android/gms/internal/zzly.class...
processing com/google/android/gms/internal/zzlz.class...
processing com/google/android/gms/internal/zzma.class...
processing com/google/android/gms/internal/zzmb.class...
processing com/google/android/gms/internal/zzmc.class...
processing com/google/android/gms/internal/zzmd.class...
processing com/google/android/gms/internal/zzme.class...
processing com/google/android/gms/internal/zzmf.class...
processing com/google/android/gms/internal/zzmg.class...
processing com/google/android/gms/internal/zzmh.class...
processing com/google/android/gms/internal/zzmi.class...
processing com/google/android/gms/internal/zzmj.class...
processing com/google/android/gms/internal/zzmk.class...
ignored resource com/google/android/gms/tagmanager/
processing com/google/android/gms/tagmanager/Container.class...
processing com/google/android/gms/tagmanager/Container$1.class...
processing com/google/android/gms/tagmanager/Container$FunctionCallMacroCallback.class...
processing com/google/android/gms/tagmanager/Container$FunctionCallTagCallback.class...
processing com/google/android/gms/tagmanager/Container$zza.class...
processing com/google/android/gms/tagmanager/Container$zzb.class...
processing com/google/android/gms/tagmanager/ContainerHolder.class...
processing com/google/android/gms/tagmanager/ContainerHolder$ContainerAvailableListener.class...
processing com/google/android/gms/tagmanager/DataLayer.class...
processing com/google/android/gms/tagmanager/DataLayer$1.class...
processing com/google/android/gms/tagmanager/DataLayer$2.class...
processing com/google/android/gms/tagmanager/DataLayer$zza.class...
processing com/google/android/gms/tagmanager/DataLayer$zzb.class...
processing com/google/android/gms/tagmanager/DataLayer$zzc.class...
processing com/google/android/gms/tagmanager/DataLayer$zzc$zza.class...
processing com/google/android/gms/tagmanager/InstallReferrerReceiver.class...
processing com/google/android/gms/tagmanager/InstallReferrerService.class...
processing com/google/android/gms/tagmanager/PreviewActivity.class...
processing com/google/android/gms/tagmanager/PreviewActivity$1.class...
processing com/google/android/gms/tagmanager/TagManager.class...
processing com/google/android/gms/tagmanager/TagManager$1.class...
processing com/google/android/gms/tagmanager/TagManager$2.class...
processing com/google/android/gms/tagmanager/TagManager$3.class...
processing com/google/android/gms/tagmanager/TagManager$4.class...
processing com/google/android/gms/tagmanager/TagManager$zza.class...
processing com/google/android/gms/tagmanager/zza.class...
processing com/google/android/gms/tagmanager/zza$1.class...
processing com/google/android/gms/tagmanager/zza$2.class...
processing com/google/android/gms/tagmanager/zza$zza.class...
processing com/google/android/gms/tagmanager/zzaa.class...
processing com/google/android/gms/tagmanager/zzab.class...
processing com/google/android/gms/tagmanager/zzac.class...
processing com/google/android/gms/tagmanager/zzae.class...
processing com/google/android/gms/tagmanager/zzaf.class...
processing com/google/android/gms/tagmanager/zzag.class...
processing com/google/android/gms/tagmanager/zzah.class...
processing com/google/android/gms/tagmanager/zzai.class...
processing com/google/android/gms/tagmanager/zzaj.class...
processing com/google/android/gms/tagmanager/zzak.class...
processing com/google/android/gms/tagmanager/zzal.class...
processing com/google/android/gms/tagmanager/zzam.class...
processing com/google/android/gms/tagmanager/zzan.class...
processing com/google/android/gms/tagmanager/zzao.class...
processing com/google/android/gms/tagmanager/zzap.class...
processing com/google/android/gms/tagmanager/zzaq.class...
processing com/google/android/gms/tagmanager/zzar.class...
processing com/google/android/gms/tagmanager/zzas.class...
processing com/google/android/gms/tagmanager/zzat.class...
processing com/google/android/gms/tagmanager/zzau.class...
processing com/google/android/gms/tagma<message truncated>

Hi,
I was facing the same issue. I was searching and found that this problem normally occurs if there are .jar or .aar files with same name, or sometimes classes inside them.

I was unable to find until, I started doing it manually file by file.

I am using Facebook SDK, AdMob SDK and UnityAds asset to be specific.

I found that there were a .jar and a .aar file was there in FB and one of the other SDK with same name, but different versions (You see, that’s why any duplicate finder will be unable to locate it).

Name of my files were:
support-v4-23.x.x.aar and support-v4-25.x.x.aar
support-annotations-23.x.x.jar and support-annotations-25.x.x.jar

I deleted one .aar and one .jar file, the ones with lower versions. And it worked.

Hope it helps.