cherry-pick(4.3-stable): guard preserveMountedTags against resolveView throwing (#9649)#9827
Merged
Merged
Conversation
…ng (#9649) Fixes #9636. `NativeProxy.preserveMountedTags` assumes `FabricUIManager.resolveView` returns `null` for a tag whose view isn't mounted: ```kotlin for (i in tags.indices) { if (mFabricUIManager.resolveView(tags[i]) == null) { tags[i] = -1 } } ``` In practice `resolveView` (→ `SurfaceMountingManager.getView`) **throws `IllegalViewOperationException`** when the tag's `ViewState` is already registered but the Android view object hasn't been created yet. That uncaught throw on the main thread is fatal. This is reachable when a view is **mid-preallocation** and a third-party view manager dispatches an event **synchronously from inside `createView`**, re-entering Reanimated's event path before the view exists. `lottie-react-native` does exactly this: when a composition is already in Lottie's in-memory cache, `setAnimation` fires `onAnimationLoaded` synchronously during `createViewInstance`, which dispatches through `FabricEventDispatcher` → `NodesManager.onEventDispatch` → `performOperations` → `preserveMountedTags` → `resolveView` on the tag that is still being preallocated. Observed crash: ``` com.facebook.react.uimanager.IllegalViewOperationException: Unable to find view for tag N. Surface 1 stopped: false, rootViewAttached: true at com.facebook.react.fabric.mounting.SurfaceMountingManager.getView at com.facebook.react.fabric.FabricUIManager.resolveView at com.swmansion.reanimated.NativeProxy.preserveMountedTags at com.swmansion.reanimated.NativeProxy.performOperations (Native Method) ... at com.airbnb.android.react.lottie.LottieAnimationViewManagerImpl.sendAnimationLoadedEvent at com.airbnb.lottie.LottieAnimationView.setComposition ... at com.facebook.react.fabric.mounting.SurfaceMountingManager.createViewUnsafe at com.facebook.react.fabric.mounting.SurfaceMountingManager.preallocateView ``` The fix wraps the `resolveView` call in a try/catch and treats `IllegalViewOperationException` the same as the existing `null` branch — the tag has no usable view yet, so mark it `-1`. This matches the intent of the original null check (a tag without a mounted view is dropped) and is the minimal hot-fix that eliminates the crash. As @bartlomiejbloniarz noted in the issue, this path can eventually be removed once the pull model lands on Android. Minimal standalone Expo repro (crashes within ~1s of launch on Android, New Architecture, before this change; no crash with it applied): **https://github.com/audrius-savickas/lottie-reanimated-9636-repro** ```bash npm install npx expo run:android ``` It mounts several `Animated.createAnimatedComponent(LottieView)` instances with `entering`/`exiting` and remounts them every 250 ms, with the Lottie source bundled locally so the first remount is a guaranteed cache hit (the synchronous `onAnimationLoaded` during preallocation). Full captured trace is in [`CRASH-STACKTRACE.txt`](https://github.com/audrius-savickas/lottie-reanimated-9636-repro/blob/main/CRASH-STACKTRACE.txt). Versions matching the production crash: `react-native@0.85.3` (New Arch), `react-native-reanimated@4.3.1`, `react-native-worklets@0.8.3`, `lottie-react-native@7.3.4`. Co-authored-by: audrius.sav <audrius.savickas@eneba.com> Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com> (cherry picked from commit 502cf70)
wisniewskij
approved these changes
Jul 2, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Cherry-picking for Reanimated 4.3.2 release
Cherry-pick notes
4.3-stable still has the Java
NativeProxy.java(the Kotlin migration landed after 4.3 branched), so the same try/catch guard aroundresolveViewwas applied to the JavapreserveMountedTagsinstead ofNativeProxy.kt.