firebase-ios-sdk: Messaging.messaging().token returns errors

Hi all, I’ll be raising this to the team, and see what we can do here. Thanks.

Following up with some guidance for the Firebase 10.4.0 SDK.

As stated in the release notes, 10.4.0 onwards, we are declining vending a FCM token until an APNS token is provided. We have always been logging a WARNING when this has occurred in previous versions of the SDK but haven’t declined to provide a FCM token. Such a vended FCM token is not useful since it is missing a target APNS token and thus has no endpoint to send the pushes to.

Scenarios:

1. On a fresh install of the app, Firebase configure flow triggers the FCM register flow even though there isn’t a APNS token. You will see an error message due to this flow. This error can be ignored as the FCM token is refetched once an APNS token is provided. I am investigating if this can be fixed in a future SDK release.

UPDATE Mar 1, 2023: This has been fixed in 10.6.0 - https://github.com/firebase/firebase-ios-sdk/pull/10789

1. For Objective C or Swift (not SwiftUI) projects, if swizzling is enabled, FCM token refetch happens automatically when we get the APNS token. The swizzling will take care of listening for when APNS token is available. The FCM messaging delegate callback will be called once an FCM token is available.

func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?)

1. If swizzling is disabled or if your project is pure SwiftUI (swizzling does not work well with SwiftUI projects) You must implement the UIApplicationDelegate callbacks to listen for APNS token availability. Check the SwiftUI sample in the FCM SDK codebase for how to achieve this.

2. Testing: If you have unit or integration tests running in the simulator, it is not possible to get an APNS token unless specific environment is used - iOS 16 Simulator + macOS 13 + Apple Silicon HW. If that environment condition is not met, there isn’t an APNS token available in iOS simulator. As a result, any tests for fetching FCM token will error out in the Firebase 10.4.0 SDK. Either reconsider the tests or try to provide fake APNS token for test purposes only. If you provide a fake APNS token, be sure to delete any FCM token created from this process. Example - the FIRMessagingPubSubTest in the Firebase SDK uses a fake APNS token.

facing same issue in my flutter app. FCM just stopped working with the following error

FLTFirebaseMessaging: An error occurred while calling method Messaging#getToken, errorOrNil => {
    NSLocalizedFailureReason = "Invalid fetch response, expected 'token' or 'Error' key";
}
[VERBOSE-2:dart_vm_initializer.cc(41)] Unhandled Exception: [firebase_messaging/unknown] An unknown error has occurred.
#0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:653:7)
#1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:315:18)
<asynchronous suspension>
#2      MethodChannel.invokeMapMethod (package:flutter/src/services/platform_channel.dart:518:43)
<asynchronous suspension>
#3      MethodChannelFirebaseMessaging.getToken (package:firebase_messaging_platform_interface/src/method_channel/method_channel_messaging.dart:224:11)
<asynchronous suspension>
#4      _MyAppState.requestAndRegisterNotification (package:myapp/main.dart:174:23)

Can we say this is a firebase thingy for sure?

@aashishpatil-g It is understood, but they cannot make a change so drastic that it breaks applications that are already in production without sending a warning that they will make a change that can break functionality if they do not do the following

The same problem occurs with flutter applications using firebase_messaging

@Seanmclem and @yeahse so i removed the GoogleServices-info.plist file from my Runner folder, then i did flutter clean and clean build folder then flutter pub get and it worked, yet to replace the GoogleServices-info.plist file , i i’m thinking the GoogleServices-info.plist file is corrupt don’t know how or if this ever happens will replace it and let you know if it still works

I solved it❗️

In fact, the notification deviceToken(APNs Key) injection time was slower than the time to call token(_:).

Like you, it happened a few days ago on iOS16 devices

You should check the timing of the called functions.

An update has been made to the Firebase SDK to provide an APN token at launch on the latest SDK release (https://firebase.google.com/support/release-notes/ios) Obviously, this modification applies even if we are not using the latest version of the SDK. This also applies to older versions which should not be the case…

Same issue here. We notice an error spike on firebase crashlytics as we send the error

This server change has been pulled back for now. It might take a few hours for it to propagate.

I need to confirm this,

Does anyone have the error on a physical device in production ?

cause it seem to me that the error has to do with Simulator not being a physical device and returns null value as its APN token🤔

Yes, this is happening in production on IOS devices. Both simulators and real devices are causing the same error.

Maybe Certs are expired…the Apple APN keys are setup, and my Dev and Prod ones are invalid. One in expired last month in December, and the prod one expired Today.

This was the exact error I was getting. the expected 'token' or 'Error' key one.

EDIT: didn’t fix it

But… @kishanbarmawala this reads the same as “I have decided to continue creating invalid FCM tokens in our project, by permanently relying on outdated versions of the software” - I mean that in a technical sense, I believe those are technically valid substitutions in your statement. I totally understand if it is just deferring the maintenance to a future date when project timelines allow but I would be careful adopting that version pin permanently…

I verify that things work now with firebase-ios-sdk for version 10.3.0 after rolling back the server change (thank you! That takes the pressure off us over at react-native-firebase, we appreciate it), but I still show an issue when attempting to qualify firebase-ios-sdk 10.4.0

Specifically, I see this when our e2e test suite exercises the Obj-C API and makes a call to deleteToken:

The operation couldn’t be completed. No APNS token specified before fetching FCM Token

Okay, that appears to be somewhat expected based on the discussion in this issue and in the related changelog for 10.4.0 firebase-ios-sdk release, however, what I am personally missing (and thus cannot fix for the react-native-firebase community) is some guidance on exactly why the APNS token might be null (despite swizzling being in effect…) and how to forcibly fetch (or re-fetch) an APNS token in order to allow further work with FCM tokens

In our test app we are registered for remote notifications, so we should receive APNS tokens, and swizzling is on, so firebase-ios-sdk should be receiving the APNS tokens for messaging. I’m not sure what else we need to do to handle this change and adopt 10.4.0 but would love a hint

Thanks

[Update: our native code had conditionals that detected simulator and cut-out from the remote notification registration / APNS token fetch flows, so it would never get an APNS token of course! On an M1 mac with macOS 13 + iOS 16 Simulator we can get APNS tokens and everything works even on Simulator now when those conditions are met. We will fake an APNS token for other Simulators, and try to improve dev experience with better messaging for the other cases where APNS token may not be available]

The change log for Version 10.4.0 - January 17, 2023 says:

On app startup, an APNs Token must be provided to FCM SDK before retrieving an FCM Token, otherwise an error will be returned as part of the completion.

I tried this and it seems to be working for me as of Firebase v8.15:

Not sure if this is the right thing to do though. I hope Firebase updates their documentation to match the recent changes.

P.S. I also tried to find and upload my old APNs Auth Key and downloaded the GoogleServices-info.plist file (which turned out to be exactly same), therefore I don’t know if any of these actions were required in addition to the change in code I mentioned above.

UPD: After the rollback the problem is gone from our live app, which is on Firebase 8.12. The build patched as described above and on Firebase 8.15 works fine as well.

@henryadebayo I was able to fix it based on your reply, so thanks! However, I was thinking about the plist thing -and felt like it was unlikely that all of our GoogleServices-info.plist files are suddenly corrupt in the past 5 days. So rather than deleting it -I did the other part you mentioned. I stopped and restarted my app. Not even a full rebuild, just a new JS bundle (I’m using React Native), so a quick stop and restart, also closed and re-opened simulator.

The only other thing we have in common is we both just re-added our APN certificates. So that might be required too, but afterwards restarting the build was definitely the final thing that fixed it for me.

@henryadebayo Just tried it too, and no change either.

@Seanmclem chaged APNs key Ali but it did not fix the issue maybe it may work you

I’m having the same issues, any tips on how to solve it?

Up here also. @aashishpatil-g if you can give us more infos about the case of this evolution will be live again. Which SDK version, when, etc… However thank you for reactivity

@Monsteel are you using Swift?

Yes I using Swift.

@Monsteel please tell how you solved it, and are you using react or flutter ?

Using Swift. My app is Native app.

You shold check Messaging.messaging ().apnsToken = deviceToken called timing, and Messaging.messaging().token(completion:) called timing

It’ll probably be called late Messaging.messaging ().apnsToken = deviceToken than Messaging.messaging().token(completion:)

because,UNUserNotificationCenterDelegate began to receive late.

I need to confirm this,

Does anyone have the error on a physical device in production ?

cause it seem to me that the error has to do with Simulator not being a physical device and returns null value as its APN token🤔

What’s really strange is that I also use the same codebase with a different bundle id (my preprod environment) and I don’t get the error. I checked the Firebase plist but it is up to date.

This makes it even more curious, since the same exact thing is happening to me. In one of the environments it works flawlessly, the other is failing constantly!

Similar issue: https://github.com/invertase/react-native-firebase/issues/6830