Firebase-auth - Can't get the number of an unknown enum value

[mathieuedet]

[REQUIRED] Step 2: Describe your environment

• Android Studio version: Android Studio Quail 1 | 2026.1.1
• Firebase Component: Authentication
• Component version: 24.0.1

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

On app startup, the application eagerly initializes Firestore (which forces FirebaseAuth initialization). For only one 1-2 users (for about 50 000 users) — appears to be those with pre-existing persisted auth state written by a previous SDK version — FirebaseAuth.
throws while (de)serializing an internal protobuf enum, crashing the whole app at Application.onCreate.

It is not reproducible on a fresh install / signed-out state; it only reproduces for this user with existing persisted auth state, which is why we cannot trigger it on demand. It is a hard, non-recoverable startup crash for affected users.

The failure is:

java.lang.IllegalArgumentException: Can't get the number of an unknown enum value.
     at com.google.android.gms.internal.firebase-auth-api.zzxz.zza(com.google.firebase:firebase-auth@@24.0.1:2)
     at com.google.android.gms.internal.firebase-auth-api.zzxh$zzb.zza(com.google.firebase:firebase-auth@@24.0.1:35)
     at com.google.android.gms.internal.firebase-auth-api.zzxh$zzb$zza.zza(com.google.firebase:firebase-auth@@24.0.1:11)
     at com.google.android.gms.internal.firebase-auth-api.zzbm.zzb(com.google.firebase:firebase-auth@@24.0.1:130)
     at com.google.android.gms.internal.firebase-auth-api.zzbm.zzd(com.google.firebase:firebase-auth@@24.0.1:143)
     at com.google.android.gms.internal.firebase-auth-api.zzbm.zzd(com.google.firebase:firebase-auth@@24.0.1:143)
     at com.google.android.gms.internal.firebase-auth-api.zzbw.zza(com.google.firebase:firebase-auth@@24.0.1:2)
     at com.google.android.gms.internal.firebase-auth-api.zzmy$zza.zza(com.google.firebase:firebase-auth@@24.0.1:18)
     at com.google.firebase.auth.internal.zzby.zzb(com.google.firebase:firebase-auth@@24.0.1:7)
     at com.google.firebase.auth.internal.zzcb.zza(com.google.firebase:firebase-auth@@24.0.1:81)
     at com.google.firebase.auth.FirebaseAuth.<init>(com.google.firebase:firebase-auth@@24.0.1:349)
     at com.google.firebase.auth.FirebaseAuthRegistrar.lambda$getComponents$0(com.google.firebase:firebase-auth@@24.0.1:11)
     at com.google.firebase.components.ComponentRuntime.lambda$discoverComponents$0(...)
     at com.google.firebase.firestore.auth.FirebaseAuthCredentialsProvider.<init>(FirebaseAuthCredentialsProvider.java:78)
     at com.google.firebase.firestore.FirebaseFirestore.newInstance(FirebaseFirestore.java:196)
     at com.google.firebase.firestore.FirebaseFirestore.getInstance(FirebaseFirestore.java:129)
     at <our code>.ProfileRepositoryImpl.<init>(ProfileRepositoryImpl.kt)   // calls FirebaseFirestore.getInstance()
     ... (Hilt-injected @Singleton created during Application.onCreate)
 Caused by: java.lang.IllegalArgumentException: Can't get the number of an unknown enum value.

Relevant Code:

Crash is reached simply by initializing Firestore, which forces FirebaseAuth init.

private val firestore = FirebaseFirestore.getInstance() 

It seems to be introduced since we have updated firebase-bom from 34.5.0 to 34.12.0

Thanks a lot.

[lehcar09]

Hi @mathieuedet, thank you for reaching out. I tried to replicate the issue by using the Firebase version you shared, however, I wasn't able to encounter the issue.

Looking through our release notes, I don't see any changes in Firebase Auth from BoM version 34.5.0 to 34.12.0 that might have caused this. There is an issue reported prior to Firebase Auth 24.0.1 about the additional encryption to Firebase Authentication data inside Android persistent storage to enhance the security. But, it looks to me that this error is not related to that.

From what I gather, this could be due to corrupted local cache file. Let me consult this to our engineers and get back to you. Thanks!

[mathieuedet]

Additional info: it's possible that the user is coming from an old version and that the problem isn't really related to 34.5.0–34.12.0. It seems that this crash was happening few month ago for same user when I had migrated firebase-bom from 34.3.0 to to 34.5.0