[Bug] FirebaseCrashlytics | Error serializing key/value metadata.

[bilck]

[REQUIRED] Please fill in the following fields:

• Unity editor version: 2020.3.13f1
• Firebase Unity SDK version: 8.0.0
• Source you installed the SDK: .unitypackage
• Problematic Firebase Component: Crashlytics
• Other Firebase Components in use: Analytics, RemoteConfig, Messaging
• Additional SDKs you are using: Playfab, ARCore, DevToDev
• Platform you are using the Unity editor on: Windows
• Platform you are targeting: Android
• Scripting Runtime: IL2CPP

[REQUIRED] Please describe the issue here:

We are getting the following error on our Android builds:

Error serializing key/value metadata.
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1441)
	at java.util.HashMap$EntryIterator.next(HashMap.java:1475)
	at java.util.HashMap$EntryIterator.next(HashMap.java:1473)
	at java.util.Collections$UnmodifiableMap$UnmodifiableEntrySet$1.next(Collections.java:1708)
	at java.util.Collections$UnmodifiableMap$UnmodifiableEntrySet$1.next(Collections.java:1701)
	at org.json.JSONObject.<init>(JSONObject.java:138)
	at com.google.firebase.crashlytics.internal.common.p.a(Unknown Source:2)
	at com.google.firebase.crashlytics.internal.common.p.a(Unknown Source:7)
	at com.google.firebase.crashlytics.internal.common.CrashlyticsController$9.a(Unknown Source:19)
	at com.google.firebase.crashlytics.internal.common.CrashlyticsController$9.call(Unknown Source:0)
	at com.google.firebase.crashlytics.internal.common.CrashlyticsBackgroundWorker$3.then(Unknown Source:2)
	at com.google.android.gms.tasks.h.run(Unknown Source:26)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
	at com.google.firebase.crashlytics.internal.common.l$1$1.a(Unknown Source:2)
	at com.google.firebase.crashlytics.internal.common.b.run(Unknown Source:5)
	at java.lang.Thread.run(Thread.java:923)

Steps to reproduce:

Just open the app and this exception will be logged.

We don't know exactly which CustomKey is triggering this issue. It would be very helpful to log which Key had issues when being serialized.

We double-checked and no Keys or values exceed 1024 characters.

[paulinon]

Hi @bilck,

In order to identify what's causing this behavior, could you provide a minimal, reproducible example of your project along with the steps taken before facing this issue?

[bilck]

HI @paulinon,

Unfortunately right now I can't work on reproducing this example, but I can provide you with a development APK or access to our repository. Would that work for you?

[paulinon]

Hi @bilck,

That would be great. Make sure you also include the steps taken before facing this issue.

[bilck]

Is an development APK enough to investigate the issue?

This exception seems that it is caused by multiple metadata being set at the same time.
Would setting 10+ metadata at the same time be an issue? The Unity Firebase SDK only supports setting one custom data at a time (Crashlytics.SetCustomKey).