Error when trying to build APK for app

Question

I get this error when I try to build my app in Android Studio

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

com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: retrofit2/BuiltInConverters$BufferingResponseBodyConverter.class

Here are my dependencies:

compile 'com.android.support:appcompat-v7:24.2.1'
compile 'com.android.support:design:24.2.1'
compile 'com.google.firebase:firebase-core:9.0.2'
compile 'com.google.firebase:firebase-analytics:9.0.2'
compile 'com.google.firebase:firebase-config:9.0.2'
compile 'com.google.firebase:firebase-auth:9.0.2'
compile 'com.google.android.gms:play-services:9.0.2'
compile 'com.google.android.gms:play-services-appindexing:9.0.2'
compile 'com.google.firebase:firebase-database:9.0.2'
compile 'com.google.code.gson:gson:2.8.0'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.google.android.gms:play-services-maps:9.0.2'
compile 'com.android.support.constraint:constraint-layout:+'
compile 'com.android.support:multidex:1.0.1'

Answer 1

What you showed looks good.

According to the error, you have duplicate converter class.

Remove any retrofit jars in you libs folder, then run gradle build again

Answer 2

It seems like some jar files are not compiled properly.

Try to clean or Rebuild the project

If it doesn't help than remove the jar file and try to add it again

I am sure it will help

Answer 3

Remove the gson library u have added separately. Only the one with the retrofit is required.