[firebase_messaging]: 16.5.0 never receives APNs token under UIScene (apns-token-not-set) — regression from 16.4.3

[kylehuang17]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

Messaging

Which platforms are affected?

iOS

Description

After upgrading firebase_messaging from 16.4.3 to 16.5.0, physical iOS devices running a UIScene-based Flutter app never receive the APNs device token, so FCM tokens can never be obtained and push notifications are completely broken.

• FirebaseMessaging.instance.getAPNSToken() returns null indefinitely (polled every 500ms for 3s, still null 11+ seconds after launch).
• FirebaseMessaging.instance.getToken() throws [firebase_messaging/apns-token-not-set] APNS token has not been received on the device yet.
• onTokenRefresh never fires.
• Notification permission is already authorized; aps-environment entitlement is present (development for debug, production for release); pushes to previously-obtained tokens still arrive, so certificates/entitlements are fine.

This is a regression from 16.4.3: the identical app (same UIScene setup, same AppDelegate, same entitlements) ran in production alongside UIScene for five months on 16.4.3 with working push. The only change was the plugin upgrade to 16.5.0. Pinning back to 16.4.3 immediately restores APNs token delivery on the same device.

We did apply the new 16.5.0 UIScene guidance: FLTFirebaseMessagingPlugin.configureNotificationCenterDelegate() is called in application(_:didFinishLaunchingWithOptions:) before returning super.... That fixes the notification-center delegate setup, but the APNs device token registration path (didRegisterForRemoteNotificationsWithDeviceToken → FIRMessaging) still appears to be broken under scene-based lifecycle — the token never reaches the SDK.

App setup:

• Info.plist contains UIApplicationSceneManifest with UISceneDelegateClassName = FlutterSceneDelegate (adopted 5 months ago, worked with 16.4.3).
• AppDelegate: FlutterAppDelegate, FlutterImplicitEngineDelegate (plugins registered in didInitializeImplicitFlutterEngine).
• Method swizzling enabled (no FirebaseAppDelegateProxyEnabled key; no manual didRegisterForRemoteNotifications forwarding).
• setAutoInitEnabled(true) is called explicitly at startup.

Reproducing the issue

1. Flutter app with UIScene adoption (UIApplicationSceneManifest + FlutterSceneDelegate) and FlutterAppDelegate + FlutterImplicitEngineDelegate.
2. firebase_messaging: 16.5.0, call FLTFirebaseMessagingPlugin.configureNotificationCenterDelegate() in didFinishLaunchingWithOptions per the 16.5.0 README.
3. Run on a physical iPhone with notification permission granted.
4. Call getAPNSToken() (null forever) then getToken() → throws apns-token-not-set.
5. Downgrade only firebase_messaging to 16.4.3 (and remove the 16.5-only delegate call) → APNs token arrives, getToken() succeeds.

Firebase Core version

4.x (Podfile.lock: Firebase iOS SDK 12.17.0)

Flutter Version

3.41.9 (stable)

Relevant Log Output

[firebase_messaging/apns-token-not-set] APNS token has not been received on the device yet. Please ensure the APNS token is available by calling `getAPNSToken()`.

Additional context and comments

Workaround for anyone hitting this: pin firebase_messaging: 16.4.3 and remove/comment the configureNotificationCenterDelegate() call (16.5-only API).

[SelaseKay]

Hi @kylehuang17, thanks for the report. We'll investigate this further.

[SelaseKay]

Hi @kylehuang17, I followed your steps to reproduce the issue on my end using the firebase_messaging example app, but I wasn't able to reproduce it.

Have you tried running the app on a different iOS device? If so, was the issue still reproducible? Also, have you tried reproducing it with Flutter 3.44.0?

If the issue persists, could you please share a minimal reproducible example that I can run locally? That would help me investigate this further. Thanks!

[elau8465]

Confirming this on a second app and a different physical device, and notably without the configureNotificationCenterDelegate() call — so the regression doesn't depend on having adopted the 16.5.0 UIScene guidance.

Environment

• firebase_messaging 16.4.0 → 16.5.0, as part of a wider FlutterFire bump
• firebase_core 4.13.0, Firebase iOS SDK 12.17.0 (CocoaPods; SPM disabled)
• Flutter 3.44.9 stable, Dart 3.12.2
• Physical iPhone 16 Pro (iPhone17,1), iOS 26.6
• UIApplicationSceneManifest with a SceneDelegate: FlutterSceneDelegate subclass
• AppDelegate: FlutterAppDelegate, FlutterImplicitEngineDelegate, plugins registered in didInitializeImplicitFlutterEngine
• Swizzling enabled (no FirebaseAppDelegateProxyEnabled key)
• aps-environment: development, notification permission already granted

Symptom

Our registration path only polls once getNotificationSettings() reports authorized, so permission is confirmed granted at the time of the call. Polling getAPNSToken() 40 × 300ms:

Runner  flutter: APNs token unavailable after 12125ms
Runner  flutter: APNs token unavailable after 12114ms

Null for the full 12s, on both calls within a single launch. onTokenRefresh never fires and no FCM token is ever obtained. The same device registered normally on the previous build.

Re: Flutter 3.44 — reproduces on 3.44.9 stable, so this isn't specific to 3.41.x.

Difference from the original report: we never called FLTFirebaseMessagingPlugin.configureNotificationCenterDelegate(). The original report applied that guidance and still lost the token; we never applied it and also lost the token. So the APNs device-token path appears broken under scene lifecycle independently of notification-center delegate setup.

Pinning firebase_messaging: 16.4.3 while leaving firebase_core 4.13.0 / Firebase iOS SDK 12.17.0 and every other FlutterFire plugin at their latest resolves cleanly in CocoaPods and restores APNs token delivery on the same device — which also isolates this to the messaging plugin rather than the 12.17.0 SDK bump.

No standalone minimal repro yet; happy to put one together if the config above isn't enough to go on.