Crash on iOS: Attempt to unmount a view which has a different index

[terrysahaidak]

Before submitting a new issue

• I tested using the latest version of the library, as the bug might be already fixed.
• I tested using a supported version of react native.
• I checked for possible duplicate issues, with possible answers.

Bug summary

While scrolling in out chat that use legendlist and recycles views, had this crash:

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Attempt to unmount a view which has a different index. (parent: <EaseView: 0x15b72d500; frame = (56 4; 100 61); transform3D = [1, 0, 0, 0; 0, 1, 0, 0; 0, 0, 1, -0.00078125; 0, 0, 0, 1]; tag = 25006; backgroundColor = UIExtendedSRGBColorSpace 1 1 1 1; layer = <CALayer: 0x15b608e40>>, child: <RCTParagraphComponentView: 0x30aadce00; frame = (58.3333 34; 32.6667 17); opaque = NO; tag = 26048; layer = <CALayer: 0x15d8bd7a0>; attributedText = 15:28{
    EventEmitter = {length = 8, bytes = 0x180c182a01000000};
    NSBackgroundColor = "UIExtendedSRGBColorSpace 0 0 0 0";
    NSColor = "UIExtendedSRGBColorSpace 0.388235 0.384314 0.443137 1";
    NSFont = "<UICTFont: 0x156cb0c80> font-family: \".SFUI-Regular\"; font-weight: normal; font-style: normal; font-size: 12.00pt";
    NSKern = "0.2";
    NSParagraphStyle = "Alignment Left, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 16.8/16.8, LineHeightMultiple 0 LineBreakMode WordWrapping, Tabs (\n    28L,\n    56L,\n    84L,\n    112L,\n    140L,\n    168L,\n    196L,\n    224L,\n    252L,\n    280L,\n    308L,\n    336L\n), DefaultTabInterval 0, Blocks (\n), Lists (\n), BaseWritingDirection Natural, HyphenationFactor 0, TighteningForTruncation NO, HeaderLevel 0 LineBreakStrategy 0 PresentationIntents (\n) ListIntentOrdinal 0 CodeBlockIntentLanguageHint ''";
}>, index: 2, actual index: 0, tag at index: 24990)'
*** First throw call stack:
(0x198a6e23c 0x19553d224 0x19659f2b0 0x10e122bd8 0x10e073acc 0x10e073514 0x10e0734b8 0x10e073484 0x10e073450 0x10e07341c 0x10e072c54 0x10ea64c70 0x10ea63f7c 0x10ea63db0 0x10e06c784 0x10e06c454 0x10e06bdc4 0x10e5cec48 0x100fac544 0x100fc5ccc 0x100fe7748 0x100fbc204 0x100fbc144 0x1989fb030 0x198988604 0x19898754c 0x23e0ef498 0x19e680244 0x19e5eb158 0x19e7f7618 0x10d1ff330 0x10d1ff2a0 0x10d2002b0 0x195595c1c)
terminating due to uncaught exception of type NSException
warning: could not execute support code to read Objective-C class data in the process. This may reduce the quality of type information available.

Library version

0.7.2

Environment info

System:
  OS: macOS 26.5.1
  CPU: (10) arm64 Apple M1 Max
  Memory: 102.08 MB / 32.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.20.2
    path: /Users/terrysahaidak/.nvm/versions/node/v20.20.2/bin/node
  Yarn:
    version: 4.12.0
    path: /Users/terrysahaidak/.yarn/bin/yarn
  npm:
    version: 10.8.2
    path: /Users/terrysahaidak/.nvm/versions/node/v20.20.2/bin/npm
  Watchman:
    version: 2026.01.12.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /Users/terrysahaidak/.rvm/gems/ruby-3.3.6/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.2
      - iOS 26.2
      - macOS 26.2
      - tvOS 26.2
      - visionOS 26.2
      - watchOS 26.2
  Android SDK:
    API Levels:
      - "28"
      - "29"
      - "30"
      - "31"
      - "32"
      - "33"
      - "34"
      - "35"
      - "36"
    Build Tools:
      - 28.0.3
      - 30.0.2
      - 30.0.3
      - 31.0.0
      - 32.0.0
      - 33.0.0
      - 33.0.1
      - 34.0.0
      - 35.0.0
      - 35.0.1
      - 36.0.0
    System Images:
      - android-32 | Google Play ARM 64 v8a
      - android-34 | Google APIs ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2025.2 AI-252.27397.103.2522.14514259
  Xcode:
    version: 26.3/17C529
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.10
    path: /Library/Java/JavaVirtualMachines/zulu-17.jdk/Contents/Home/bin/javac
  Ruby:
    version: 3.3.6
    path: /Users/terrysahaidak/.rvm/rubies/ruby-3.3.6/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.1.3
    wanted: 20.1.3
  react:
    installed: 19.2.0
    wanted: 19.2.0
  react-native:
    installed: 0.83.6
    wanted: 0.83.6
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Steps to reproduce

Not sure what exactly is the step to reproduce, we use legendlist with recycling so perhaps it's the reason? But this is the first time i had this crash.

Reproducible example repository

None

[janicduplessis]

We don’t do anything special on view unmount so I am not sure it is a bug in ease. Are you able to consistently repro? If so could you try to remove the ease views in the list and see if it still happens?