Unable to load script from assets 'index.android.bundle'. Make sure your bundle is packaged correctly or you're running a packager server. App crash in release build only

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• Search for existing issues: https://github.com/facebook/react-native/issues
• Use the latest React Native release: https://github.com/facebook/react-native/releases

Environment

Done in 2.05s. - /usr/local/bin/yarn
      npm: 6.4.1 - /usr/local/bin/npm
      Watchman: 4.7.0 - /usr/local/bin/watchman
    SDKs:
      iOS SDK:
        Platforms: iOS 12.0, macOS 10.14, tvOS 12.0, watchOS 5.0
      Android SDK:
        Build Tools: 23.0.1, 23.0.2, 23.0.3, 24.0.2, 25.0.0, 25.0.2, 25.0.3, 26.0.1, 26.0.2, 27.0.3, 28.0.0, 28.0.2, 28.0.3
        API Levels: 22, 23, 24, 25, 26, 27, 28
    IDEs:
      Android Studio: 3.2 AI-181.5540.7.32.5056338
      Xcode: 10.0/10A255 - /usr/bin/xcodebuild
    npmPackages:
      react: 16.5.0 => 16.5.0
      react-native: 0.57.1 => 0.57.1
    npmGlobalPackages:
      create-react-native-app: 2.0.2
      react-native-cli: 2.0.1

Description

I get the error below on release builds. I don’t see the issue in my dev environment i.e. react-native run-android. I installed the apk on my Pixle 2 XL - Android Pi and the app immediately crashes. I got the error below from my Firebase console (Crashlytics)

Fatal Exception: java.lang.RuntimeException: Unable to load script from assets 'index.android.bundle'. Make sure your bundle is packaged correctly or you're running a packager server.
       at com.facebook.react.bridge.CatalystInstanceImpl.jniLoadScriptFromAssets(CatalystInstanceImpl.java)
       at com.facebook.react.bridge.CatalystInstanceImpl.loadScriptFromAssets(CatalystInstanceImpl.java:216)
       at com.facebook.react.bridge.JSBundleLoader$1.loadScript(JSBundleLoader.java:32)
       at com.facebook.react.bridge.CatalystInstanceImpl.runJSBundle(CatalystInstanceImpl.java:243)
       at com.facebook.react.ReactInstanceManager.createReactContext(ReactInstanceManager.java:1114)
       at com.facebook.react.ReactInstanceManager.access$900(ReactInstanceManager.java:116)
       at com.facebook.react.ReactInstanceManager$5.run(ReactInstanceManager.java:913)
       at java.lang.Thread.run(Thread.java:764)

Reproducible Demo

Let us know how to reproduce the issue. Include a code sample, share a project, or share an app that reproduces the issue using https://snack.expo.io/. Please follow the guidelines for providing a MCVE: https://stackoverflow.com/help/mcve

[vinnyhoward]

For me this combination worked using "react-native": "0.59.4"

• In gradle-wrapper.properties add distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.1-all.zip
• in root build.gradle use classpath 'com.android.tools.build:gradle:3.3.0'
• in app build.gradle I have:

project.ext.react = [
        entryFile: "index.js",
        bundleAssetName: "index.android.bundle",
        bundleInAlpha: true,
        bundleInBeta: true
]

right above apply from: "../../node_modules/react-native/react.gradle"

[sryze]

For some reason I had import com.facebook.react.BuildConfig; in my MainAplication file (I guess due to some smart ass auto import fixing feature of IntelliJ), and therefore BuildConfig.DEBUG was set to false. Because of this:

    public boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }

React Native was always trying to load index.android.bundle from the app pacakge, not from the dev server. Removing the import com.facebook.react.BuildConfig line fixed the issue for me 🎆 🍺 👍