[firebase_auth]: java.util.ConcurrentModificationException

[rohansohonee1]

[READ] Step 1: Are you in the right place?

Issues filed here should be about bugs in the code in this repository. If you have a general
question, need help debugging, or fall into some other category use one of these other channels:

• For general technical questions, post a question on StackOverflow
  with the firebase tag.
• For general Firebase discussion, use the
  firebase-talk google group.
• For help troubleshooting your application that does not fall under one of the above categories,
  reach out to the personalized Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Android Studio version: Android Studio Koala Feature Drop | 2024.1.2 Patch 1
  Non-Bundled Plugins:
  Dart (241.18968.26)
  io.flutter (85.0.1)
• Firebase Component: firebase_core, firebase_auth
• Component version: 4.0.0, 6.0.0

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

Issue was previously opened #5643 however is closed and locked now.

Please check the stacktrace below reported via firebase crashlytics.

com.agendaboa.app_issue_2a613512125591f1195354d519518214_crash_session_68C314BB02FC00017847CA6809454AE3_DNE_0_v2_stacktrace.txt

Device
Brand:Motorola
Model:Moto G15
Orientation:Portrait
RAM free: 1.03 GB
Disk free: 175.02 GB
Operating System
Version:Android 15
Orientation:Portrait
Rooted: No
Crash
Date:Sep 11, 2025, 11:58:24 PM

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[lehcar09]

Hi @rohansohonee1, thank you for reaching I tried reproducing the issue, however, I wasn't able to encounter the error. By any chance, were you able to reproduce the issue? Could you share code snippet that might've trigger the exception? Thanks!

[rohansohonee1]

@lehcar09 Issue is from our users. I don't have the reproducible steps for this crash.

[lehcar09]

Got it. Based on stacktrace, it looks to me that this is a race condition. I’ll raise this to our engineers and see what we can do here. Thanks!