Firebase Crashlytics have been reporting this crash on huge number of devices having Android 8 and Android 6 on playstore. We are using dexguard in the app too.
Environment and Components I am using are as below.
Project build.gradle
classpath 'com.google.firebase:firebase-crashlytics-gradle:2.2.0' // Crashlytics plugin
classpath 'com.google.firebase:perf-plugin:1.3.1' // Performance Monitoring plugin
App build.gradle
implementation 'com.google.firebase:firebase-messaging:20.2.1'
implementation 'com.google.firebase:firebase-analytics:17.4.3'
implementation 'com.google.firebase:firebase-crashlytics:17.1.0'
implementation 'com.google.firebase:firebase-perf:19.0.7'
These are the logs I am getting from Crashlytics.
???
com.google.firebase.installations.FirebaseInstallations.INotificationSideChannel$Stub$Proxy
Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
at com.google.firebase.installations.FirebaseInstallations.INotificationSideChannel$Stub$Proxy(:452)
at com.google.firebase.installations.FirebaseInstallations.INotificationSideChannel$Stub$Proxy(:331)
at com.google.firebase.installations.FirebaseInstallations.INotificationSideChannel$Stub$Proxy(:296)
at com.google.firebase.installations.FirebaseInstallations$$Lambda$3.run(:2)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
It is not giving any hint so we can reproduce that crash on our devices but It is causing to a huge number of users.