react-native: Cannot resolve symbol 'ReactNativeFlipper' - When building release build variant

In my case when I need to building release app, I just make a copy ReactNativeFlipper.java to android/app/src/main/java/com/my_project/ReactNativeFlipper.java then I can building it.

ReactNativeFlipper.java content:

package com.myProject;
import android.content.Context;
import com.facebook.react.ReactInstanceManager;
public class ReactNativeFlipper {
  public static void initializeFlipper(Context context, ReactInstanceManager reactInstanceManager) {
    // Do nothing as we don't want to initialize Flipper on Release.
  }
}

Just comment this code when you only want to run on emulator and undo when you want to build in release

Hi guys, I have the same issue and this is the way I fix it.

People who create a project using npx react-native init this_is_package_name.

1. If you guys haven’t changed the package name, please feel free to try the solution from Hermanyo comment
2. If you guys changed the package name, please pay attention at the top import of ReactNativeFlipper.java in release folder

import this_is_NEW_package_name; // <= please change this import

Hope my comment can help people that have the same issue as me

In my case when I need to building release app, I just make a copy ReactNativeFlipper.java to android/app/src/main/java/com/my_project/ReactNativeFlipper.java then I can building it.

This is not the solution and will result in deplicated class + crash at developer time. You should have only two ReactNativeFlipper.java files:

android/app/src/debug/java/com/helloworld/ReactNativeFlipper.java
android/app/src/release/java/com/helloworld/ReactNativeFlipper.java

You can copy the content from the template. If the issue persists open a separate issue.

In my case when I need to building release app, I just make a copy ReactNativeFlipper.java to android/app/src/main/java/com/my_project/ReactNativeFlipper.java then I can building it.

ReactNativeFlipper.java content:

package com.myProject;
import android.content.Context;
import com.facebook.react.ReactInstanceManager;
public class ReactNativeFlipper {
  public static void initializeFlipper(Context context, ReactInstanceManager reactInstanceManager) {
    // Do nothing as we don't want to initialize Flipper on Release.
  }
}

This file solves the assembleRelease but crashes when I try to run react-native run-android because is a duplicated class.

Any solution at this point? I can’t find it.

After some investigating, I realized that I was not adding a release folder that contained that ReactNativeFlipper.java code.

I was missing this file in src/release/com/packagename/ReactNativeFlipper.java

https://raw.githubusercontent.com/react-native-community/rn-diff-purge/release/0.71.1/RnDiffApp/android/app/src/release/java/com/rndiffapp/ReactNativeFlipper.java

Closing the issue now.

My issue was that I renamed my package, but did not update the package structure in the release directory (note that there are debug, main AND release directories).

I had the same issue and @LuongTruong comment helped me solve it, so even if this issue is closed, I’m going to write this down in case someone else has this issue.

I had everything set up correctly between main, debug and release folders. My issue was that my app has flavors, and app package ids end with .dev, .qa and .prod. I was not changing app package id in ReactNativeFlipper.java file correctly for .qa and .prod release builds, so the release build did not now what ReactNativeFlipper class was as it had a different package id. When I added modifying package id for that file in my build scripts, everything started working again.