Inconsistency between local and UIKit touch registries

[mvrty]

Description

When using a ScrollView inside a formSheet modal on iOS (react-navigation, react-native-screens), when dragging to dismiss the modal, (sometimes) the app crashes with *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Inconsistency between local and UIKit touch registries'.

(Might be issue in react-navigation/rn-screens but posting here since it's react-native/React/Fabric/RCTSurfaceTouchHandler.mm:206 that crashes it.)

Note: I can only re-produce this with latest xcode beta and iOS 26 - can't reproduce on iOS 18.

Steps to reproduce

Run the reproducer, open the modal, scroll to close (when scrollview has been scrolled) - in some situations it will crash.

React Native Version

0.81.0

Affected Platforms

Runtime - iOS

Areas

Fabric - The New Renderer

Output of npx @react-native-community/cli info

System:
  OS: macOS 15.5
  CPU: (16) arm64 Apple M4 Max
  Memory: 100.09 MB / 64.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 22.12.0
    path: ~/.nvm/versions/node/v22.12.0/bin/node
  Yarn:
    version: 4.9.2
    path: ~/.nvm/versions/node/v22.12.0/bin/yarn
  npm:
    version: 10.9.0
    path: ~/.nvm/versions/node/v22.12.0/bin/npm
  Watchman:
    version: 2025.04.28.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.2
    path: /Users/mn/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.5
      - iOS 18.5
      - macOS 15.5
      - tvOS 18.5
      - visionOS 2.5
      - watchOS 11.5
  Android SDK:
    API Levels:
      - "30"
      - "31"
      - "32"
      - "33"
      - "34"
      - "35"
    Build Tools:
      - 33.0.0
      - 34.0.0
      - 35.0.0
    System Images:
      - android-33 | Google APIs ARM 64 v8a
      - android-35 | Google Play ARM 64 v8a
      - android-35 | Pre-Release 16 KB Page Size Google Play ARM 64 v8a
      - android-35 | Pre-Release 16 KB Page Size Google APIs ARM 64 v8a
      - android-36 | Google Play ARM 64 v8a
      - android-36 | Pre-Release 16 KB Page Size Google Play ARM 64 v8a
    Android NDK: 22.1.7171670
IDEs:
  Android Studio: 2024.3 AI-243.26053.27.2432.13536105
  Xcode:
    version: 16.4/16F6
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.4.1
    path: /Users/mn/.sdkman/candidates/java/current/bin/javac
  Ruby:
    version: 2.7.5
    path: /Users/mn/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.0
    wanted: 20.0.0
  react:
    installed: 19.1.0
    wanted: 19.1.0
  react-native:
    installed: 0.81.0
    wanted: 0.81.0
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Stacktrace or Logs

*** Assertion failure in -[RCTSurfaceTouchHandler _updateTouches:](), /Users/mn/Code/Play/rctSurfaceTh/node_modules/react-native/React/Fabric/RCTSurfaceTouchHandler.mm:206
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Inconsistency between local and UIKit touch registries'
*** First throw call stack:
(
	0   CoreFoundation                      0x00000001804f39e8 __exceptionPreprocess + 172
	1   libobjc.A.dylib                     0x000000018009c084 objc_exception_throw + 72
	2   Foundation                          0x000000018100dd38 -[NSMutableDictionary(NSMutableDictionary) classForCoder] + 0
	3   rctSurfaceTh.debug.dylib            0x000000010452ff48 -[RCTSurfaceTouchHandler _updateTouches:] + 528
	4   rctSurfaceTh.debug.dylib            0x00000001045327b0 -[RCTSurfaceTouchHandler touchesCancelled:withEvent:] + 124
	5   UIKitCore                           0x0000000185d08a6c -[UIGestureRecognizer _componentsCancelled:withEvent:] + 348
	6   UIKitCore                           0x00000001862c8ad4 -[UIEvent _removeGestureRecognizersSendingCancelledEvent:] + 624
	7   UIKitCore                           0x0000000185d0f888 -[UIGestureRecognizer gestureNode:didUpdatePhase:] + 240
	8   Gestures                            0x000000022ece15f8 GFGestureNodeDefaultValue + 4468
	9   Gestures                            0x000000022ecfe7a4 _swift_stdlib_malloc_size + 26208
	10  Gestures                            0x000000022ed28ff8 __swift_memcpy24_8 + 20672
	11  Gestures                            0x000000022ed50858 GFGestureNodeCoordinatorCreate + 2148
	12  UIKitCore                           0x0000000185cfc828 -[UIGestureEnvironment _updateForEvent:window:] + 468
	13  UIKitCore                           0x000000018625ce44 -[UIWindow sendEvent:] + 2796
	14  UIKitCore                           0x000000018623b280 -[UIApplication sendEvent:] + 376
	15  UIKitCore                           0x00000001862cf540 __dispatchPreprocessedEventFromEventQueue + 1184
	16  UIKitCore                           0x00000001862d21f4 __processEventQueue + 4800
	17  UIKitCore                           0x00000001862ca7a0 updateCycleEntry + 168
	18  UIKitCore                           0x000000018573a6b4 _UIUpdateSequenceRunNext + 120
	19  UIKitCore                           0x000000018614131c schedulerStepScheduledMainSectionContinue + 56
	20  UpdateCycle                         0x00000002513e92b4 _ZN2UC10DriverCore18continueProcessingEv + 80
	21  CoreFoundation                      0x00000001804114ac __CFMachPortPerform + 164
	22  CoreFoundation                      0x000000018044dbe0 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 56
	23  CoreFoundation                      0x000000018044d1f8 __CFRunLoopDoSource1 + 480
	24  CoreFoundation                      0x000000018044c2c0 __CFRunLoopRun + 2100
	25  CoreFoundation                      0x0000000180446e24 _CFRunLoopRunSpecificWithOptions + 496
	26  GraphicsServices                    0x00000001924c19bc GSEventRunModal + 116
	27  UIKitCore                           0x00000001862217a8 -[UIApplication _run] + 772
	28  UIKitCore                           0x00000001862259d0 UIApplicationMain + 124
	29  UIKitCore                           0x00000001854ab528 block_destroy_helper.15 + 5120
	30  rctSurfaceTh.debug.dylib            0x0000000103e3f1a4 $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ + 128
	31  rctSurfaceTh.debug.dylib            0x0000000103e3f114 $s12rctSurfaceTh11AppDelegateC5$mainyyFZ + 44
	32  rctSurfaceTh.debug.dylib            0x0000000103e3fa40 __debug_main_executable_dylib_entry_point + 28
	33  dyld                                0x00000001008653d0 start_sim + 20
	34  ???                                 0x0000000100a56b98 0x0 + 4305808280
)
libc++abi: terminating due to uncaught exception of type NSException
terminating due to uncaught exception of type NSException
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Inconsistency between local and UIKit touch registries'
CoreSimulator 1047 - Device: iPhone 16 Pro (E2B61D7F-69C6-42CC-B992-67B71E6443FB) - Runtime: iOS 26.0 (23A5308g) - DeviceType: iPhone 16 Pro

MANDATORY Reproducer

https://github.com/mvrty/rct-surface-touch-handler-issue

Screenshots and Videos

rctoutput.mov

[react-native-bot]

Warning

Could not parse version: We could not find or parse the version number of React Native in your issue report. Please use the template, and report your version including major, minor, and patch numbers - e.g. 0.76.2.

[react-native-bot]

Warning

Could not parse version: We could not find or parse the version number of React Native in your issue report. Please use the template, and report your version including major, minor, and patch numbers - e.g. 0.76.2.

[mvrty]

In RCTSurfaceTouchHandler.mm - do we need to assert in _updateTouches? Can it be treated as a no-op to avoid crashes? Also remove the assert from _unregisterTouches and _activeTouchesFromTouches. Not sure if this would break anything else?

[mvrty]

Seems to be fixed here. software-mansion/react-native-screens#3133