Migrate Unity app from Fabric Crashlytics to Firebase Crashlytics

This quickstart describes how to migrate your existing Fabric Crashlytics Unity app to Firebase Crashlytics so that you can see all of your crash reports in the Firebase console.

Before you begin

The following guide assumes that you have a working Unity app with Fabric. If you do not have an existing Unity app in Fabric, follow the Get Started instructions for users new to Crashlytics.

Step 1: Link your Fabric app(s)

Sign into Fabric, then navigate to the migration flow.
Check that the Signed into Google as field lists the Google account associated with your Firebase project. If it doesn't, click Switch accounts to select the correct account.
Click Get Started, then click Start Linking.
Drag the appropriate Fabric App on the left into the appropriate Firebase project on the right.

Note that you can also create a new Firebase project.
Click Link 1 app to Firebase.

Step 2: Remove Fabric

Fabric adds GameObjects to your Scene to initialize Crashlytics in your game as well as additional directories for the SDKs themselves.

To ensure there are no conflicts between the Fabric Crashlytics and Firebase Crashlytics plugins, remove the following Fabric folders and files from your Unity project:

Under Assets, delete the following files:

Assets/
   Editor Default Resources/
       FabricSettings.asset     <- DELETE
   Fabric/                      <- DELETE
   Plugins/
       Android/
           answers/             <- DELETE
           beta/                <- DELETE
           crashlytics/         <- DELETE
           crashlytics-wrapper/ <- DELETE
           fabric/              <- DELETE
           fabric-init/         <- DELETE
       iOS/
           Fabric/              <- DELETE

In the Hierarchy Window, remove the following GameObjects

SampleScene
    Main Camera
    Directional Light
    Canvas
    EventSystem
    FabricInit                  <- DELETE
    CrashlyticsInit             <- DELETE

Remove all Fabric entries in Assets > Plugins > Android > AndroidManifest.xml.

For example, a known key to remove is: android:name="io.fabric.unity.android.FabricApplication"

Search and remove other Fabric entries if they exist.

Step 3: Add Firebase config files

Navigate to the Firebase console.
In the top left-hand corner next to Project Overview, click , then select Project Settings
For your newly linked apps, download your platform-specific Firebase configuration file(s) for each app that you linked. For a single Unity project, you can have at most two config files.
- For iOS — GoogleService-Info.plist
- For Android — google-services.json
In your Unity project, open the Project window, then move your config file(s) into the Assets folder.

Note: You can place the Firebase config files anywhere within the Assets folder.

Step 4: Add the Firebase Crashlytics SDK

Download the Firebase Unity SDK, then unzip the SDK somewhere convenient.

The Firebase Unity SDK is not platform-specific.
In your open Unity project, navigate to Assets > Import Package > Custom Package.
From the unzipped SDK, select to import the Crashlytics SDK (FirebaseCrashlytics.unitypackage). Make sure you have FirebaseCrashlytics.unitypackage version 6.15.0 or later (if not, update the Asset package version). This is required for your crash reports to appear in the Firebase console.
- Unity 5.x and earlier: Use the .NET 3.x framework, so import dotnet3/FirebaseCrashlytics.unitypackage.
- Unity 2017.x and later: Allow the use of the .NET 4.x framework. If your Unity project uses .NET 4.x, import dotnet4/FirebaseCrashlytics.unitypackage.
Note that you can import any other supported Firebase product as well.
In the Import Unity Package window, click Import.

Important: With the Firebase Unity SDK for iOS, do not disable method swizzling. Swizzling is required by the SDK; without it, key Firebase features (such as FCM token handling) do not function properly.
Create a new C# script, then add it to a GameObject in the scene.
1. Open your first scene, then create an empty GameObject named CrashlyticsInitializer.
2. Click Add Component in the Inspector for the new object.
3. Select your CrashlyticsInit script to add it to the CrashlyticsInitializer object.

Initialize Crashlytics in the script's Start method:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// Import Firebase
using Firebase;

public class CrashlyticsInit : MonoBehaviour {
  // 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.
          }
          else
          {
              UnityEngine.Debug.LogError(System.String.Format(
                "Could not resolve all Firebase dependencies: {0}",dependencyStatus));
              // Firebase Unity SDK is not safe to use here.
          }
      });
  }

// Update is called once per frame
void Update()
  // ...
}

With the SDK added and initialized, Crashlytics automatically gets to work listening for and collecting crash reports.

Step 5: Initialize Firebase Crashlytics

Create a new C# script, then add it to a GameObject in the scene.
1. Open your first scene, then create an empty GameObject named CrashlyticsInitializer.
2. Click Add Component in the Inspector for the new object.
3. Select your CrashlyticsInit script to add it to the CrashlyticsInitializer object.

Initialize Crashlytics in the script's Start method:

  using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;

  // Import Firebase
  using Firebase;

  public class CrashlyticsInit : MonoBehaviour {
      // 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.
              }
              else
              {
                  UnityEngine.Debug.LogError(System.String.Format(
                    "Could not resolve all Firebase dependencies: {0}",dependencyStatus));
                  // Firebase Unity SDK is not safe to use here.
              }
          });
      }

    // Update is called once per frame
    void Update()
      // ...
  }

With the SDK added and initialized, Crashlytics automatically gets to work listening for and collecting crash reports.

Step 6: Replace Fabric API calls

Review the following SDK changes and make the appropriate updates to your code:

Crashlytics now rotates IDs based on Firebase installation IDs

Crashlytics uses the Crashlytics Installation UUID to identify instances of your app and to associate your users' data with their devices. Previously, Crashlytics rotated your user's Installation UUID when the advertising ID of their device changed. Now, Crashlytics rotates the Installation UUID based on the user's Firebase installation ID (FID). For more information, visit Manage Firebase installation IDs.

Reason for change

Using FIDs is consistent with other Firebase SDKs.

Fabric.Crashlytics is now Firebase.Crashlytics

We've changed our namespace from Fabric to Firebase.

Fabric

using Fabric.Crashlytics;

Firebase

using Firebase.Crashlytics;

RecordCustomException is now LogException

Log custom non-fatal exceptions that were caught and handled.

Fabric

Crashlytics.RecordCustomException(string name, string reason, StackTrace stackTrace);
Crashlytics.RecordCustomException(string name, string reason, string stackTraceString);

Firebase

Crashlytics.LogException(Exception ex);

Reason for change

This function is most often used to log an instance of an Exception. Rather than requiring you to extract the "name", "reason", and "stackTrace" manually (which results in superfluous code), you can now provide the instance of the Exception and Firebase Crashlytics will extract the information that it needs.

Workaround

If you were leveraging these parameters in a way other than just pulling the information directly off of an exception, you can still accomplish the previous behavior by creating your own Exception subclass with the custom metadata in its description.

SetKeyValue is now SetCustomKey

Set any key/value pair to send along with your crash report. Re-setting the same key will update the value.

Fabric

Crashlytics.SetKeyValue(string key, string value);

Firebase

Crashlytics.SetCustomKey(string key, string value);

Reason for change

This method is being renamed to make its behavior more clear and to improve consistency with other Firebase APIs.

SetUserIdentifier is now SetUserId

Set a user identifier to help understand which user experienced a crash.

Fabric

Crashlytics.SetUserIdentifier(string identifier);

Firebase

Crashlytics.SetUserId(string identifier);

Reason for change

This method is being renamed to improve consistency with other Firebase APIs. As a bonus, it's shorter; who doesn't love shaving off key strokes?

SetUserEmail and SetUserName are removed

Previously, you were allowed to set a name or email associated with a crash using explicit methods. These will no longer be explicitly defined.

Fabric

Crashlytics.SetUserEmail(string email);
Crashlytics.SetUserName(string name);

Reason for change

Google strives to protect customer data, and part of that effort is designing APIs that do the same for developer tooling. These user-specific APIs have been removed to encourage the use of generated and non-personally identifying methods for discerning which user was affected by a crash.

Workaround

To specify which user experienced a crash, the preferred method is to use SetUserId. However, if this is not a tenable solution, the same functionality can be accomplished using SetCustomKey.

Crash and ThrowNonFatal are removed

Previously, Crashlytics provided two utility methods to throw exceptions for testing purposes. These will not be included in Firebase Crashlytics.

Fabric

Crashlytics.Crash();
Crashlytics.ThrowNonFatal();

Reason for change

Crashlytics for Unity runs in many different environments, and many different kinds of crashes can occur. These methods did not clearly specify whether the resulting crashes occurred in C# or in the underlying platform-specific native SDK.

Workaround

Test your implementation— Test your Crashlytics setup by forcing a crash to generate a crash report in the Firebase console.

Step 7: Build your project

Export your project to iOS or to Android.

After the export is complete, verify that the project exported correctly by comparing your exported project to the example export configurations below.

If it seems like files are missing after comparing your project, open your Unity Editor, then run the Google Play Services Resolver (find the instructions below).

iOS

Example export configuration to an Xcode workspace

Verify that dependencies and structure look correct:

YOUR_EXPORT_DIRECTORY/
    build/
    Classes/
    Data/
    GoogleService-Info.plist                      <- FIREBASE CONFIG FILE
    Info.plist
    ...
    Libraries/
        ...
        Plugins/
            iOS/
                Firebase/
                    libCrashlyticsiOSWrapper.a    <- CRASHLYTICS LIBRARY
                    libFirebaseCppApp.a           <- FIREBASE CORE LIBRARY
        ...
    ...
    Podfile
    Podfile.lock
    Pods/                                         <- DEPENDENCIES
        FirebaseCrashlytics/
        Firebase/
        FirebaseAnalytics/
        FirebaseCore/
        FirebaseInstanceID/
        GoogleAppMeasurement/
        GoogleUtilities/
        ...
    Unity-iPhone/
    Unity-iPhone Tests/
    Unity-iPhone.xcodeproj
    Unity-iPhone.xcworkspace                      <- COCOAPODS WORKSPACE
    UnityData.xcassets

Android

Example export configuration to an Android Studio project

Verify that dependencies and structure look correct:

YOUR_EXPORT_DIRECTORY/
    build/
    build.gradle
    ...
    Firebase/                                    <- FIREBASE FOR UNITY
    gradle/
    gradle.properties
    gradlew.bat
    libs/                                        <- DEPENDENCIES
        com.google.android.gms.play-services*
        com.google.firebase.firebase-crashlytics-*
        com.google.firebase.firebase-crashlytics-unity-*
        com.google.firebase.firebase-*
    ...
    src/

Example export configuration to APK

Open your APK in Android Studio, then verify that dependencies and structure look correct:

lib/
   x86/
       libunity.so
       libmono.so
       libFirebaseCppApp-VERSION.so            <- FIREBASE CORE LIBRARY
       libmain.so
   armeabi-v7a/
       libunity.so
       libmono.so
       libFirebaseCppApp-VERSION.so            <- FIREBASE CORE LIBRARY
       libmain.so
assets/
classes.dex
res/
resources.arsc
AndroidManifest.xml
firebase-*.properties                          <- FIREBASE PROPERTIES
play-services*.properties                      <- GMS PROPERTIES

Run the resolver if files are missing after export (as needed)

The Google Play Services Resolvers make sure that your Unity project has the appropriate dependencies for exporting your app to iOS or to Android. For more information on the resolver, visit the README for the Unity Jar Resolver.

View platform-specific instructions for running the resolver

iOS

The iOS Resolver runs automatically and leverages Cocoapods to put iOS dependencies in the exported Pods directory.

To download Cocoapods to your machine:
- Navigate to Assets > Play Services Resolver > iOS Resolver > Install Cocoapods
To enable or disable generation of podfiles (optional):
- Navigate to Assets > Play Services Resolver > iOS Resolver > Settings

Android

The Android Resolver runs automatically and leverages gradle to put Android dependencies in Assets/Plugins/Android.

To manually run the resolver:
- Navigate to Assets > Play Services Resolver > Android Resolver > Resolve
To enable or disable auto-resolution (enabled by default):
- Navigate to Assets > Play Services Resolver > Android Resolver > Settings

Next steps

Test your implementation— Test your Crashlytics setup by forcing a crash to generate a crash report in the Firebase console.
Customize crash reports— Crashlytics automatically starts collecting crash reports as soon as you add the SDK, but you can also customize your setup by adding opt-in reporting, logs, keys, and even tracking of non-fatal errors.
Learn about API Changes— See how Crashlytics has evolved from Fabric Crashlytics to Firebase Crashlytics.
Add Google Analytics— Combine the power of Google Analytics with Firebase Crashlytics to see the Crash Free Users statistics in the Firebase console.