ZipException: duplicate entry: com/google/android/gms/internal/zzbtt.class

Question

Error:Execution failed for task \':app:transformClassesWithJarMergingForDebug\'.

com.android.build.api.transform.TransformException: java.util.zip.Zip

Answer 1

1. Please make sure all Firebase and Google play services are the exact same version (11.0.2, for example)

2. Refer to the FirebaseUi github for a table of the correct versions to use for Firebase 11.0.2

3. Unrelated, but your Volley library dependency is deprecated (see it's respective Github page). Similarly, you shouldn't need Volley if using Apache HTTP libraries

Answer 2

This help me ./gradlew :app:dependencies and you will see all your dependencies like this:

|    +--- com.google.android.gms:play-services-gcm:+ -> 11.0.4
|  |    +--- com.google.android.gms:play-services-analytics:+ -> 11.0.4
|    \--- com.google.android.gms:play-services-location:+ -> 11.8.0

and you have to find wrong versions. In my case it was location:+ -> 11.8.0 and i my fix it in app/build.gradle like this

compile('com.google.android.gms:play-services-location:11.0.4') {
   force = true;
}