Gradle Error:Execution failed for task ':app:processDebugGoogleServices'

I'v got a same issue. but Now I'm fixed.

You should delete a line apply plugin: 'com.google.gms.google-services'

because "com.android.application" package already has same package.

I had the same issue and resolved it by adding the following line in the dependencies of the project-level build.gradle:

classpath 'com.google.gms:google-services:3.0.0'

For a full working example, check out the following project on github.

Hope this helps :)

I was finding the same error complaining about mixing google play services version when switching from 8.3 to 8.4. Bizarrely I saw reference to the app-measurement lib which I wasn't using.

I thought maybe one of my app's dependencies was referencing the older version so I ran ./gradlew app:dependencies to find the offending library (non were).

But at the top of task output I found a error message saying that the google plugin could not be found and defaulting to google play services 8.3. I used the sample project @TheYann linked to compare. My setup was identical except I applied the apply plugin: 'com.google.gms.google-services' at the top my app's build.gradle file. I moved to bottom of the file and that fixed the gradle compile error.