Unity Firebase Crashlytics not sending any crash reports, getting "failed to retrieve settings" error on logcat - firebase

Question

Unity editor version: 2019.3.15f1
Firebase Unity SDK version: firebase_unity_sdk_6.15.2
Additional SDKs im using: Unity IAP, Gamesparks, Ironsource, Facebook, Appsflyer, GameAnalytics
Platform im using the Unity editor on: Windows
Platform im targeting: Android
Scripting Runtime: IL2CPP
Problem
I am getting data on firebase analytics, but I cannot get crashlytics to report anything. Im stuck on this...
Steps to reproduce:
Add the firebase analytics and crashlytics sdks.
Add the google-services.json GoogleService-Info.plist files somewhere in assets folder
Add this code to initialise the firebase
// Use this for initialization
void Start ()
{
// Initialize Firebase
Firebase.FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task => {
var dependencyStatus = task.Result;
if (dependencyStatus == Firebase.DependencyStatus.Available)
{
// Create and hold a reference to your FirebaseApp,
// where app is a Firebase.FirebaseApp property of your application class.
// Crashlytics will use the DefaultInstance, as well;
// this ensures that Crashlytics is initialized.
Firebase.FirebaseApp app = Firebase.FirebaseApp.DefaultInstance;
// Set a flag here for indicating that your project is ready to use Firebase.
VisualDebugger.SetText("crashlytics initialised");
}
else
{
UnityEngine.Debug.LogError(System.String.Format(
"Could not resolve all Firebase dependencies: {0}",dependencyStatus));
VisualDebugger.SetText("crashlytics NOT initialised: " + dependencyStatus);
// Firebase Unity SDK is not safe to use here.
}
});
Invoke("IsCrashEnabled", 5f);
}
void IsCrashEnabled()
{
VisualDebugger.AddLine("IsCrashlyticsCollectionEnabled: "+Firebase.Crashlytics.Crashlytics.IsCrashlyticsCollectionEnabled);
}
In order to get the app to run with the facebook sdk installed Ive added these two lines to proguard-user.txt
-keep public class com.facebook.**{public *; }
-keep public class com.facebook.internal.**{ public *; }
and commented out the following lines from mainTemplate.gradle
//implementation 'com.android.support:appcompat-v7:25.3.1' // Facebook.Unity.Editor.AndroidSupportLibraryResolver.addSupportLibraryDependency
//implementation 'com.android.support:customtabs:25.3.1' // Facebook.Unity.Editor.AndroidSupportLibraryResolver.addSupportLibraryDependency
//implementation 'com.android.support:support-v4:25.3.1' // Facebook.Unity.Editor.AndroidSupportLibraryResolver.addSupportLibraryDependency
When I run the app, firebase is initialised successfully. Also Firebase.Crashlytics.Crashlytics.IsCrashlyticsCollectionEnabled returns true.
I crash the app in a number of different ways, then open it again without reinstalling. But no crash reports are sent.
When I watch logcat when starting the app I see this error from firebase each time the app is opened
2020-09-28 16:18:59.332 25773-25847/? E/FirebaseCrashlytics: Failed to retrieve settings from https://firebase-settings.crashlytics.com/spi/v2/platforms/android/gmp/REDACTEDblahblahblah/settings

Answer 1

Update Oct 19, 2020:
Today a developer updated the issue I linked in this answer saying the Firebase team fixed a backend bug last Friday (Oct 16) that was affecting some new Unity Android apps registering w/ Firebase - likely the bug behind your issue. I had already solved the issue in my own project using the below solution, but if you haven't yet updated your project, I recommend running it again and seeing if Crashlytics is working for you now..
I've been dealing with the same issue this week in Unity 2019.4.11f1 - i see the same error message about not being able to retrieve settings, but with my specific project and appIds in the URL.
I found a solution in this Github issue, which suggests the problem is caused by the version of an android library that is a dependency for the Unity Firebase Crashlytics package. My rough understanding is that the firebase-crashlytics-unity library is a wrapper around android library firebase:firebase-crashlytics, and the unity package allows the underlying native Android code to be used from Unity. Version com.google.firebase:firebase-crashlytics:17.10.0 has issues with getting the settings for some Firebase projects on Android. Myself and several others following this issue found forcing Unity to use this specific dependency at version 17.1.1 resolved the issue.
Someone else with the same issue in the thread contacted Firebase support and was told:
The error you are seeing "Failed to retrieve settings" is related to
the SDK version being used. If you go to "Assets > Firebase > Editor>
CrashlyticsDependencies" you can manually update the SDK to point to
the latest Crashlytics SDK version 17.2.2. Please give it a try and if
you continue having issues, let me know.
It turned out this advice wasn't quite right - some of us following the thread then experienced a different issue when using the Android Crashlytics SDK version 17.2.2 with Unity crashlytics version 6.16.0. So I'd specifically recommend trying out the below suggestion or other solutions in the thread to set your Android crashlytics library to v17.1.1.
Changes I made in my project to address this:
First, I updated my unity firebase packages in the package manager to use version 6.16.0. In my project 4 packages were installed - core, analytics, crashlytics, and messaging.
Then I searched for the the Crashlytics package's dependency file - Crashlytics-Dependencies.xml (found by searching project - was in /Library/PackageCache/com.google.firebase.crashlytics#6.16.0/Firebase/Editor/ for me). This file initally had "com.google.firebase:firebase-crashlytics:17.0.0" listed, which I updated to be: "com.google.firebase:firebase-crashlytics:17.1.1".
As an extra precaution, I also added created a MyProject-Dependencies.xml file, as was suggested by a user in the thread - this file also specifies version "com.google.firebase:firebase-crashlytics:17.1.1".
Next, I modified the Unity build process to use a custom mainTemplate.gradle file to specify dependencies,
rather than using the External Dependency Resolver to manage and
embed unity packages (option in Build Settings > PlayerSettings >
Android).
I also updated the settings on the External Dependency Manager Android Ressolver:
Disabled AutoResolve and Disabled Resolve on Build (we dont want EDM updating dependencies without our knowledge when building)
I also turned disabled AndroidPackageInstallationEnabled - this has made the resolution process much faster and removed a bunch of .aar files from the android dependencies list, and hasn't caused any problems in my project.
I then ran External Dependency Resolver > Android > Force Resolve, which after the settings changes above, should now embed a list of the dependencies for the Android build into the mainTemplate.gradle file - Check this file (its in Assets/Plugins/Android) and you should now see com.google.firebase:firebase-crashlytics:17.1.1 in that list.
Also, I recommend reading this article about managing Unity Firebase dependencies from one of the Firebase developer advocates, Patrick Martin. It helped me wrap my head around how Android dependency management in Unity works, as well as how the Android gradle build process works.