react native - ios - failing app store ipv6 but can't re-produce

Question

I have an app that is developed in React Native and uses an API to handle all of the data. The app has already been approved with no problems and no crashing.

I have (after WWDC) recently done some updates to the app and tested everything locally as well on a real device. The app works fine with no crashing at all.

Apple have come back with the following response:

"Performance - 2.1 Your app crashed on iPad and iPhone running iOS 10.2 connected to an IPv6 network when we: 1. Launched app 2. Tapped"

The issue is that I cannot replicate the issue happening on my local machine (we use ipv4 at our offices) and the server is not IPv6.

I did some research and as of WWDC (2015), apps cannot be released into the store unless their APIS are on IPv6 server. However, I'm struggling to understand why this would cause the app to crash as it does work fine on my machine and on my device.

Is there a way that I can replicate the issue that apple are having? And could the issue that Apple are having be because of the IPv6 issue?

Answer 1

Had the same problem. Then figured out that my app did not handle the scenario when the push notification permissions were rejected by the user. So it is best to check if you are prompting users for any permission (when app initially start) and see if the app behaves as expected when these permission are Rejected. (My guess is that testers at apple usually declines these permission when they are testing)