AndroidRuntime: java.lang.RuntimeException: Expo encountered a fatal error: Error: [@RNC/AsyncStorage]: NativeModule: AsyncStorage is null.

Expo Development Tools
1

02-11 17:45:29.421 16524 16524 E AndroidRuntime: java.lang.RuntimeException: Expo encountered a fatal error: Error: [@RNC/AsyncStorage]: NativeModule: AsyncStorage is null.
02-11 17:45:29.421 16524 16524 E AndroidRuntime:
02-11 17:45:29.421 16524 16524 E AndroidRuntime: To fix this issue try these steps:
02-11 17:45:29.421 16524 16524 E AndroidRuntime:
02-11 17:45:29.421 16524 16524 E AndroidRuntime: • Run react-native link @react-native-async-storage/async-storage in the project root.
02-11 17:45:29.421 16524 16524 E AndroidRuntime:
02-11 17:45:29.421 16524 16524 E AndroidRuntime: • Rebuild and restart the app.
02-11 17:45:29.421 16524 16524 E AndroidRuntime:
02-11 17:45:29.421 16524 16524 E AndroidRuntime: • Run the packager with --reset-cache flag.
02-11 17:45:29.421 16524 16524 E AndroidRuntime:
02-11 17:45:29.421 16524 16524 E AndroidRuntime: • If you are using Coc
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at host.exp.exponent.experience.q.E(BaseExperienceActivity.java:7)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at host.exp.exponent.experience.a.run(Unknown Source:2)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:938)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:99)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at android.os.Looper.loop(Looper.java:223)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:7656)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
02-11 17:45:29.421 16524 16524 E AndroidRuntime: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)

2

you probably have a custom metro.config.js. be sure to follow this doc Customizing Metro - Expo Documentation

3

Sorry i am confused I am following this doc AsyncStorage - Expo Documentation

I learned from this post Migration from SDK 37 to 40 · Issue #11314 · expo/expo · GitHub
So I have change metro config like this is this below is this correct ? @notbrent

const { getDefaultConfig } = require("@expo/metro-config");

const defaultConfig = getDefaultConfig(__dirname);

module.exports = {
  transformer: {
    assetPlugins: ["expo-asset/tools/hashAssetFiles"],
  },
  resolver: {
    assetExts: [...defaultConfig.resolver.assetExts, "db"],
  },
};

Can you please be clear thanks for the help !!

4

well it depends - what does your current metro.config.js contain?

5

This is my current metro.config.js


const { getDefaultConfig } = require("@expo/metro-config");

const defaultConfig = getDefaultConfig(__dirname);

module.exports = {
  transformer: {
    assetPlugins: ["expo-asset/tools/hashAssetFiles"],
  },
  resolver: {
    assetExts: [...defaultConfig.resolver.assetExts, "db"],
  },
};

It works fine when i do expo start and run it on expo client

But when i build using expo build:android i am trying to use my apk generated it is giving me Asyncstorage null error and and app crashes

6

oh ok. then my guess is that you have an android or ios directory, or react-native-unimodules in your package.json - perhaps you tried ejecting before and then changed your mind. if you run expo diagnostics in your project you will find it will say you have a “bare” project. so remove the android and ios directories and remove the react-native-unimodules package from your project if you have it

7

ya it is a bare project

Should i delete the android and ios directory and run expo build:android try that apk ?

this my expo diagnostics

Expo CLI 4.0.17 environment info:
    System:
      OS: macOS 10.15.7
      Shell: 5.7.1 - /bin/zsh
    Binaries:
      Node: 10.15.3 - ~/.nvm/versions/node/v10.15.3/bin/node
      npm: 6.14.5 - ~/.nvm/versions/node/v10.15.3/bin/npm
      Watchman: 4.9.0 - /usr/local/bin/watchman
    Managers:
      CocoaPods: 1.10.0 - /usr/local/bin/pod
    SDKs:
      Android SDK:
        API Levels: 30
        Build Tools: 30.0.3
        System Images: android-30 | Google APIs Intel x86 Atom
    IDEs:
      Android Studio: 4.1 AI-201.8743.12.41.6953283
      Xcode: /undefined - /usr/bin/xcodebuild
    npmPackages:
      expo: ~40.0.0 => 40.0.0 
      react: 16.13.1 => 16.13.1 
      react-dom: 16.13.1 => 16.13.1 
      react-native: ^0.63.4 => 0.63.4 
      react-native-web: ~0.13.12 => 0.13.18 
    npmGlobalPackages:
      expo-cli: 4.0.17
    Expo Workflow: bare

And try Managed build

8

yes. when you run expo build:android it will tell that you cannot use that for building bare apps. we launched a preview of the next generation of our build service that you could try if you want to use a build service w/ your bare app - Expo Application Services (EAS): Build and Submit | by Brent Vatne | Exposition

otherwise if you’re using expo build:android you need to do what i said above to turn it back to managed

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