Firebase Crashlytics invalid api KEY AndroidX Gradle 3

Question

Like many people, I am not able to add my application with Firebase Crashlytics. I followed all the steps from the official documentation .

Also I previously checked and added my application to Firebase and everything is working fine.

My issue is the following:

ERROR - Crashlytics Developer Tools error.
java.lang.IllegalArgumentException: Crashlytics found an invalid API key: null. 
Check the Crashlytics plugin to make sure that the application has been added successfully! 
Contact support@fabric.io for assistance.

I have the google-services.json file set correctly.. From the official documentation, it should works now without anything else to do..

Edit - Solution

Like I said in the comments, I found the issue. It's because of the Gradle version that I was using. I moved my project to support AndroidX and I was using the latest version 3.3+ but with this version the google-services.json file is not parsed during the build phase. It is resolved with the 3.2+ version.

From Firebase team, only stable version are working.

Answer 1

Is your project built to support instant apps (ie you have a base feature module, installable module, and instant app module)? I've been dealing with this exact error for the last day and a half, and what finally fixed it for me was adding crashlytics { instantAppSupport true } to the bottom of my gradle file for my base feature module. If you are built for instant apps, this might be worth a shot.

Answer 2

Are you sure you have added the Crashlytics API Key in one of these files?

AndroidManifest.xml:

<meta-data
    android:name="io.fabric.ApiKey"
    android:value="xxxxxxxxxxxxxxxxxxxxxxxxxxx" />

Fabric Properties:

# Fabric properties file: app/fabric.properties
apiSecret=xxxxxxxxxxxxxxxxxxxxxxxxxxx
apiKey=xxxxxxxxxxxxxxxxxxxxxxxxxxx