Since from last 3 day’s we are facing this error for an iOS release build. It’s too difficult to identify this error in Production mode because in Dev mode it’s working fine say without any error, App is crashing in every release build on launch.

So, First time it was the weird situation where we surprised because previously it was working fine for both Android and iOS. We have started facing this error after upgrading to RN 0.55.4 or say in the latest version of RN.

We tried lot’s of a solution and also find issues in React Native Github repo related to this.

Read Also: How to build a Chatbot in React Native

How we Solved this Issue?

First of all, we try to find a crash report in Xcode.

  • Navigate to Xcode->Window->Devices and Simulators open it.
  • Attach your iPhone with Mac machine.
  • Select your device from the device list.
  • You will see two option view – crash log and open console.
  • click on the open console and you will see the various log of your device.
  • Now open your app and see the log you will get the crash error in the console window or you can search it via Undefined word.

So we found the error that crashing the app on launch is below:

Terminating app due to uncaught exception ‘RCTFatalException: Unhandled JS Exception: undefined is not an object (evaluating ‘’)’, reason: ‘Unhandled JS Exception: undefined is not an object (evaluating’s.View.prop…, stack

These are the setup to find the crash report. Now, the next step is how to identify in which package/library have that old syntax.

Navigate to your project root directory and paste the below command

grep -onr ""

You will find the list of all files which have that old syntax. That’s it, now go to each and every file and replace all to this and don’t forget to import it from react-native – import {ViewPropTypes} from ‘react-native’

That’s it, now rebuild your app and Enjoy!!!!!!!

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At BoTree Technologies, we build enterprise applications with our React Native team of 10+ engineers.

We also specialize in Ruby on Rails, Python, RPA, AI, Django, NodeJS and ReactJS.

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