Expo application does not start

4
votes

I'm experiencing strange behaviour with one of my apps. It builds OK, both development and production builds are tested by QA and App is approved for production deploy.

App goes live and is OK, but after a day or two no one is able to open the app (fresh install from the application markets does not solve the problem).

On Android platform the blue screen is shown (with some null pointer exception), on iOS the white screen is shown and the app is not loading (and not showing any errors).

I cannot trace the way to reproduce the problem and nothing really special can be found in the log files. It seems that our code is not getting executed at all, it fails somewhere in the expo stack. The only clue comes from Android platform. The blue screen shows the following error message:

Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference.

Expo version: 26.0.0

1
react-nativeexpo

1 Answers

2
votes

When starting, the application was trying to fetch some network resources that were not available.

I resolved the issue by adding proper error handling to the network resource fetching mechanism.

Lesson's learned. One should not assume that any network resource is always available to the application.