react-native: RCTFatal + 448 crash when testing via iOS TestFlight

• Review the documentation: https://facebook.github.io/react-native
• Search for existing issues: https://github.com/facebook/react-native/issues
• Use the latest React Native release: https://github.com/facebook/react-native/releases

Environment

React Native Environment Info:
    System:
      OS: macOS High Sierra 10.13.6
      CPU: x64 Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz
      Memory: 25.20 MB / 8.00 GB
      Shell: 3.2.57 - /bin/bash
    Binaries:
      Node: 8.10.0 - /usr/local/bin/node
      npm: 6.3.0 - /usr/local/bin/npm
      Watchman: 4.9.0 - /usr/local/bin/watchman
    SDKs:
      iOS SDK:
        Platforms: iOS 11.4, macOS 10.13, tvOS 11.4, watchOS 4.3
      Android SDK:
        Build Tools: 23.0.1, 23.0.3, 24.0.1, 25.0.1, 25.0.2, 26.0.1, 26.0.2, 26.0.3, 27.0.0, 27.0.3
        API Levels: 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27
    IDEs:
      Android Studio: 3.1 AI-173.4819257
      Xcode: 9.4.1/9F2000 - /usr/bin/xcodebuild
    npmPackages:
      react: 16.4.2 => 16.4.2 
      react-native: 0.56.0 => 0.56.0 
    npmGlobalPackages:
      react-native-cli: 2.0.1
      react-native-git-upgrade: 0.2.7

Description

I have released my app for testing by a specific group of people via Apple’s TestFlight. For most of the testers it seems to work perfect, but I had 1 person reporting a crash, I loaded into XCode and got the RCTFatal + 448 error.

Which seems to relate to:

Found in:

At this moment no idea what it is causing the crash. So no idea what code to provide.