Migrating from expo to react native crashes the app

[priyammishra]

I am migrating from an expo app to react native app. I removed all expo dependencies using npm uninstall command and now I am trying to build the local set up. Initially, I faced a lot of issues in android folder so I created a fresh react-native project using init command via react-native cli and copied the android folder from this newly created app and pasted it in my current project. I run two commands - npx react-native start and npx react-native run-android. Build is now successful but when I try to open the app, it stays there for few seconds and then it minimizes/crashes on its own. How to resolve this?

Inside abd logs, I am getting this error - AndroidRuntime: java.lang.UnsatisfiedLinkError: dlopen failed: library "libreact_featureflagsjni.so" not found

Please help me.

package.json
{
"name": "@mobile/mobile-app",
"main": "dev/index.ts",
"version": "1.0.12",
"scripts": {
"start": "react-native start",
"android": "react-native run-android --no-packager",
"start-reset": "react-native start --reset-cache",
"prepublishOnly": "node -e "const p=require('./package.json');p.main='src/index.ts';require('fs').writeFileSync('./package.json',JSON.stringify(p,null,2))"",
"postpublish": "node -e "const p=require('./package.json');p.main='dev/index.ts';require('fs').writeFileSync('./package.json',JSON.stringify(p,null,2))""
},
"dependencies": {
"react": "19.2.3",
"react-native": "0.85.2",
"@react-native/new-app-screen": "0.85.2",
"react-native-safe-area-context": "^5.5.2",
"@gorhom/bottom-sheet": "^5.2.8",
"@react-native-community/datetimepicker": "^8.6.0",
"@react-native-picker/picker": "^2.11.4",
"@react-navigation/bottom-tabs": "^7.4.0",
"@react-navigation/elements": "^2.6.3",
"@react-navigation/material-top-tabs": "^7.4.13",
"axios": ">=1.0.0",
"base-64": "^1.0.0",
"i18n-js": "^4.5.1",
"jwt-decode": "^4.0.0",
"react-native-calendars": "^1.1314.0",
"react-native-easy-grid": "^0.2.2",
"react-native-fs": "^2.20.0",
"react-native-image-zoom-viewer": "^3.0.1",
"react-native-timeline-flatlist": "^1.0.0",
"react-native-vector-icons": "^10.3.0"
},
"peerDependencies": {
"@cx-common/auth": "",
"@cx-common/env-config": "",
"@cx-common/mobile-navigation": "*",
"@react-navigation/native": ">=7.0.0",
"axios": ">=1.0.0",
"react": ">=18.0.0",
"react-native": ">=0.72.0",
"react-native-gesture-handler": ">=2.0.0",
"react-native-reanimated": ">=3.0.0",
"react-native-screens": ">=3.0.0",
"react-native-svg": ">=13.0.0"
},
"devDependencies": {
"@react-native-community/cli": "^20.1.3",
"@react-native-community/cli-platform-android": "20.1.0",
"@react-native-community/cli-platform-ios": "20.1.0",
"@react-native/metro-config": "0.85.2",
"@react-native/typescript-config": "0.85.2",
"@react-navigation/native-stack": "^7.14.11",
"@sentry/core": "^10.38.0",
"@types/base-64": "^1.0.2",
"@types/react": "~19.1.0",
"@types/react-native-vector-icons": "^6.4.18",
"@types/react-test-renderer": "^19.1.0",
"eslint": "^9.25.0",
"react-dom": "19.1.0",
"react-native-app-auth": "^8.1.0",
"react-native-gesture-handler": "~2.28.0",
"react-native-screens": "~4.16.0",
"react-native-svg": "^15.15.3",
"react-native-web": "~0.21.0",
"typescript": "^5.8.3"
},
"private": false
}

build.gradle

buildscript {
ext {
buildToolsVersion = "36.0.0"
minSdkVersion = 24
compileSdkVersion = 36
targetSdkVersion = 36
ndkVersion = "27.1.12297006"
kotlinVersion = "2.1.20"
}
repositories {
google()
mavenCentral()
}
dependencies {
classpath("com.android.tools.build:gradle")
classpath("com.facebook.react:react-native-gradle-plugin")
classpath("org.jetbrains.kotlin:kotlin-gradle-plugin")
}
}

apply plugin: "com.facebook.react.rootproject"

gradle.properties

org.gradle.jvmargs=-Xmx2048m -XX:MaxMetaspaceSize=512m
android.useAndroidX=true
reactNativeArchitectures=armeabi-v7a,arm64-v8a,x86,x86_64
newArchEnabled=true
hermesEnabled=true
edgeToEdgeEnabled=false

settings.gradle

pluginManagement { includeBuild("../node_modules/@react-native/gradle-plugin") }
plugins { id("com.facebook.react.settings") }
extensions.configure(com.facebook.react.ReactSettingsExtension){ ex -> ex.autolinkLibrariesFromCommand() }
rootProject.name = 'mobileapp'
include ':app'
includeBuild('../node_modules/@react-native/gradle-plugin')

app>build.gradle

apply plugin: "com.android.application"
apply plugin: "org.jetbrains.kotlin.android"
apply plugin: "com.facebook.react"

react {

autolinkLibrariesWithApp()

}

def enableProguardInReleaseBuilds = false

def jscFlavor = 'io.github.react-native-community:jsc-android:2026004.+'

android {
ndkVersion rootProject.ext.ndkVersion
buildToolsVersion rootProject.ext.buildToolsVersion
compileSdk rootProject.ext.compileSdkVersion

namespace "com.mobileapp"
defaultConfig {
    applicationId "com.mobileapp"
    minSdkVersion rootProject.ext.minSdkVersion
    targetSdkVersion rootProject.ext.targetSdkVersion
    versionCode 1
    versionName "1.0"
    manifestPlaceholders = [
        appAuthRedirectScheme: "com.mobileapp"
    ]
}
signingConfigs {
    debug {
        storeFile file('debug.keystore')
        storePassword 'android'
        keyAlias 'androiddebugkey'
        keyPassword 'android'
    }
}
buildTypes {
    debug {
        signingConfig signingConfigs.debug
    }
    release {
        // Caution! In production, you need to generate your own keystore file.
        // see https://reactnative.dev/docs/signed-apk-android.
        signingConfig signingConfigs.debug
        minifyEnabled enableProguardInReleaseBuilds
        proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
    }
}

}

dependencies {
implementation("com.facebook.react:react-android")

if (hermesEnabled.toBoolean()) {
    implementation("com.facebook.react:hermes-android")
} else {
    implementation jscFlavor
}

}

Mainapplication.kt

package com.mobileapp
import android.app.Application
import com.facebook.react.PackageList
import com.facebook.react.ReactApplication
import com.facebook.react.ReactNativeHost
import com.facebook.react.ReactPackage
import com.facebook.react.defaults.DefaultReactNativeHost
import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint.load
import com.facebook.soloader.SoLoader

class MainApplication : Application(), ReactApplication {

override val reactNativeHost: ReactNativeHost =
    object : DefaultReactNativeHost(this) {

        override fun getUseDeveloperSupport(): Boolean = BuildConfig.DEBUG

        override fun getPackages(): List<ReactPackage> =
            PackageList(this).packages

        override fun getJSMainModuleName(): String = "index"
    }

override fun onCreate() {
super.onCreate()

// 1. Initialize SoLoader FIRST
SoLoader.init(this, false)

// 2. Load the New Architecture after SoLoader is ready
if (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
  load()
}

}
}

Mainactivity.kt

package com.mobileapp
import android.os.Bundle
import com.facebook.react.ReactActivity
import com.facebook.react.ReactActivityDelegate
import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint.fabricEnabled
import com.facebook.react.defaults.DefaultReactActivityDelegate

class MainActivity : ReactActivity() {

override fun getMainComponentName(): String = "mobileapp"

override fun createReactActivityDelegate(): ReactActivityDelegate =
DefaultReactActivityDelegate(this, mainComponentName, fabricEnabled)
}

androidmanifest.xml

<uses-permission android:name="android.permission.INTERNET" />

<application
  android:name=".MainApplication"
  android:label="@string/app_name"
  android:icon="@mipmap/ic_launcher"
  android:roundIcon="@mipmap/ic_launcher_round"
  android:allowBackup="false"
  android:theme="@style/AppTheme"
  android:usesCleartextTraffic="true"
  android:supportsRtl="true">
  <activity
    android:name=".MainActivity"
    android:label="@string/app_name"
    android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|screenSize|smallestScreenSize|uiMode"
    android:launchMode="singleTask"
    android:windowSoftInputMode="adjustResize"
    android:exported="true">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
  </activity>
</application>