I randomly get this warning at iOS app start (i.e. not always).

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

OS: macOS Sierra 10.12.6
Node: 6.10.2
Yarn: 1.0.2
npm: 5.4.2
Watchman: 4.7.0
Xcode: Xcode 9.0 Build version 9A235
Android Studio: 2.1 AI-143.2915827

Packages: (wanted => installed)
react: ^16.0.0 => 16.0.0
react-native: ^0.49.3 => 0.49.3

Steps to Reproduce

1. Start the app

Expected Behavior

No warning

Actual Behavior

Reproducible Demo

N/A

Some packages I use

https://github.com/antoinerousseau/react-native-custom-components
https://github.com/rebeccahughes/react-native-device-info
https://github.com/evollu/react-native-fcm
https://github.com/gwmccull/react-native-polyfill
https://github.com/getsentry/react-native-sentry