Fixing Common React Native Errors: A Step-by-Step Guide

Common React Native Errors and How to Fix Them

As a React Native developer, you’re bound to encounter some errors while building your application. In this article, we’ll explore six common React Native errors, their causes, and solutions.

Error 1: Failed to Install the App

When running react-native run-android for the first time, you might encounter an error message indicating that the build process wasn’t successful. This error can be caused by using an incompatible Gradle version or misconfigured virtual devices.

To fix this error:

• Open your React Native application in a text editor like VS Code.
• Navigate to android > gradle > wrapper and edit the gradle-wrapper.properties file.
• Update the distributionUrl variable with the URL for a compatible version of Gradle.
• Run react-native run-android again to build the app using the new version.

Error 2: Unable to Load Script

This error occurs when the app’s JavaScript bundle is not available or not correctly packaged. There are several causes for this error, and we’ll explore three possible solutions:

Solution 1: Package the Bundle Correctly

• Go to {your-project-folder}/android/app/src/main/ and check if an assets folder exists. If not, create it.
• Run the following command from your project’s root folder:

bash
npx react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res


• Run react-native run-android again.

Solution 2: Use ADB Reverse

If the above solution doesn’t work, try using adb reverse to expose the TCP port on your Android device:

bash
adb reverse tcp:8081 tcp:8081


Solution 3: Add Cleartext Support

If the error persists, it might be due to a network communication problem. Add cleartext support to your AndroidManifest.xml file:

xml
<application
...
android:usesCleartextTraffic="true"
...>
</application>


Error 3: React Native Run-Android Command is Unrecognized

This error occurs when you’re not running the command in a React Native folder. To fix this:

• Ensure you navigate to your application’s root folder before running the app.
• Run npm install or yarn install to install the project dependencies.
• Try reinstalling the React Native CLI globally using npm install -g react-native-cli or yarn global add react-native-cli.

Error 4: React-Native Command Not Found

This error occurs when you don’t have the React Native CLI installed or it’s not properly configured. To fix this:

• Use npx to install the React Native CLI on demand: npx react-native init <your-project-name>.
• Try reinstalling the React Native CLI globally using npm install -g react-native-cli or yarn global add react-native-cli.

Error 5: Unrecognized Command: “Link”

This error occurs when you try to use the manual linking feature, which has been removed in React Native 0.69. To fix this:

• Use a third-party asset linking library like react-native-asset.
• Create a react-native.config file at the root level of your project folder and add the necessary configuration.

Error 6: Duplicate Resources

This error occurs when you try to generate a release APK using Android Studio and there are duplicate resources in your project. To fix this:

Solution 1: Clean the Drawable Folder

• Run ./gradlew clean from the android folder.

Solution 2: Add Helper Code

• Add the following code to your react.gradle file to prevent duplicate resource collisions:

groovy
def findDuplicates(resources) {
def duplicates = []
resources.each { resource ->
def existingResource = resources.find { it != resource && it.name == resource.name }
if (existingResource) {
duplicates.add(resource)
}
}
duplicates
}


By following these solutions, you should be able to fix common React Native errors and continue building your application.