When I upload my APK to the Google Play Store as an alpha release I immediately get the following report in my Firebase Crashlytics:
Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.toLowerCase(java.util.Locale)' on a null object reference
at com.google.firebase.database.obfuscated.zzdq.zza(com.google.firebase:firebase-database@@16.0.3:5111)
at com.google.firebase.database.obfuscated.zzdq$2.run(com.google.firebase:firebase-database@@16.0.3:143)
at java.lang.Thread.run(Thread.java:818)
There is no reference to any line in my app source code where the error originates from, but what's more is that there are no test users yet!
Is this being triggered by some automated process in the Google PlayStore which runs my app and some how causes this exception? This still begs the question of where the crash is coming from, considering there's no reference to a line in my app which originates it.
EDIT
Since firebase seems to now be providing the sources in the latest version of the database library I now get this crash report immediately after uploading
Fatal Exception: java.lang.NullPointerException
Attempt to invoke virtual method 'java.lang.String java.lang.String.toLowerCase(java.util.Locale)' on a null object reference
com.google.firebase.database.tubesock.WebSocketHandshake.verifyServerHandshakeHeaders (com.google.firebase:firebase-database@@16.0.4:111)
com.google.firebase.database.tubesock.WebSocket.runReader (com.google.firebase:firebase-database@@16.0.4:418)
com.google.firebase.database.tubesock.WebSocket.access$000 (com.google.firebase:firebase-database@@16.0.4:47)
com.google.firebase.database.tubesock.WebSocket$2.run (com.google.firebase:firebase-database@@16.0.4:143)
java.lang.Thread.run (Thread.java:818)
This is now also happening for the open beta track by the way.