Firebase Crashlytics Invalid Key Error

I want to integrate Firebase Crashlytics into my Android game (developed using Cocos2D-X engine). I have followed the steps mentioned in this link. I'm getting following error when

Solution 1:

Rolling back to "com.google.gms:google-services:4.0.1" in my project build.gradle file fixed the problem for me.

The Firebase docs say to use version 4.1.0, which if you follow will give the error above.

Solution 2:

Please note the following things, this should solve your issue:

1. Check Android Studio version, suggested version is 3.1.4.
2. Classpath (project-level build.gradle file shouldn't have any alpha or beta versions. That is because Firebase only supports stable version of Android Studio.

That said, the recommended setup of your gradle version is:

classpath 'com.android.tools.build:gradle:3.1.4'
classpath 'com.google.gms:google-services:4.1.0'

Solution 3:

Firebase Crashlytics requires the Google services Gradle plugin (com.google.gms:google-services) in your build script to process the google-services.json file at build time. However, Crashlytics does work on devices that do not have Google Play services.

I have added this line at end of build.gradle

apply plugin: 'com.google.gms.google-services'