Unable to load script Make sure you are either running a Metro server or that your bundle index android bundle is packaged correctly for release

Question

react-native run-android command terminates by leaving a message in android simulator  The message is as follows   Unable to load script Make sure you are either running a Metro server or that your bundle  index android bundle  is packaged correctly for release    What am I doing wrong

User · Answer

For me this problem started with upgrading react-native. The upgrade was necessary to add 64-bit support.

Before:
-------- 
Environment:
Node: 10.15.0
npm: 6.9.0
Watchman: 4.9.0
Xcode: Not Found
Android Studio: 3.4 AI-183.6156.11.34.5692245

Packages: (wanted => installed)
react: 16.0.0-alpha.12 => 16.0.0-alpha.12
react-native: ~0.55.2 => 0.55.4
react-native-cli: 2.0.1

After:
------
info 
React Native Environment Info:
Binaries:
Node: 10.15.0
npm: 6.9.0
Watchman: 4.9.0
SDKs:
Android SDK:
API Levels: 23, 26, 27, 28
Build Tools: 27.0.3, 28.0.3
System Images: android-28 | Google APIs Intel x86 Atom
IDEs:
Android Studio: 3.4 AI-183.6156.11.34.5692245
Xcode: /undefined - /usr/bin/xcodebuild
npmPackages:
react: ^16.8.6 => 16.9.0 
react-native: 0.59.9 => 0.59.9 
npmGlobalPackages:
create-react-native-app: 2.0.2
react-native-cli: 2.0.1

Also, One important change that I made for the upgrade was in ../android/build/build.gradle

android {
    ...
    defaultConfig {
        ...
        targetSdkVersion 28
        ...
    }
    ...
}

I had to change the targetSdkVersion from 27 to 28 following warning when I tried to upload the build(.apk) to goole play console. Little did i realise that this was the root cause of the above error for me. Immediatly answers by @tom and @tinmarfrutos made absolute sense.

I solved the problem by adding android:usesCleartextTraffic="true" to my android/app/src/debug/AndroidManifest.xml

User · Answer

If you are on linux open the terminal from the App root directory and run  npm start   then open another terminal window and run   react-native run-android

User · Answer

Like most of us I assume you are running on VSCODE  In my case  I ran  npx react-native start  from a seperate terminal Now run npx react-native run-android from your terminal in VSCODE

User · Answer

This is caused whenever the android device cannot reach the metro server  If the above doesn t work  check to see that your android device doesn t have a proxy configured   Settings  gt  Proxy  gt  No Proxy

User · Answer

In my case  I ve set a proxy in my emulator  It works back to normal after I removing that proxy

User · Answer

update this part in metro blacklist  var sharedBlacklist        node modules      react      dist              website  node modules          heapCapture  bundle  js            tests

User · Answer

possibility of this error is also the wrong path check once    export ANDROID HOME  Users microrentindia Library Android sdk   export PATH  PATH  ANDROID HOME tools  ANDROID HOME platform-tools

User · Answer

I got the same issue  after following the following steps  it got resolved the issue   Clear watchman watches  watchman watch-del-all   Delete the node modules folder  rm -rf node modules  amp  amp  npm install   Reset Metro Bundler cache  rm -rf  tmp metro-bundler-cache-   Remove haste cache  rm -rf  tmp haste-map-react-native-packager-

User · Answer

Apparently  none of the answers fixed the issue for me  I was able to run the react-native app on emulator but the same code  even when the Server was running   gave me this error when running the app on the device  I was able to resolve it by executing the following command in the terminal  adb reverse tcp 8081 tcp 8081

User · Answer

Quick Answer   After try to solve this problem in my workspace I found a solution   This error is because there are a problem with Metro using some combinations of NPM and Node version   You have 2 alternatives    Alternative 1  Try to update or downgrade npm and node version  Alternative 2   Go to this file   node modules metro-config src defaults blacklist js and change this code   var sharedBlacklist        node modules     react     dist             website  node modules          heapCapture  bundle  js            tests             and change to this   var sharedBlacklist        node modules      react      dist              website  node modules          heapCapture  bundle  js            tests                Please note that if you run an npm install or a yarn install you need to change the code again

User · Answer

I experienced this just because my Wifi was mistakenly turned off on my emulator i turned it back on and it started working fine  Hope it s helpful to someone

User · Answer

if you have everything correctly configured then try this   adb reverse tcp 8081 tcp 8081  Why   When the RN packager is running  there is an active web server accessible in your browser at 127 0 0 1 8081  It s from this server that the JS bundle for your application is served and refreshed as you make changes  Without the reverse proxy  your phone wouldn t be able to connect to that address    all credits to Swingline0

User · Answer

The error message on the emulator is kind of misleading  In my case  I used a Macbook  I needed to change the permissions on android gradlew by running   chmod 755   gradlew  and then the app could be built and deployed to the android emulator

User · Answer

I have also faced this issue  I resolved this following step   Check android sdk path in Environment Veritable   Add ANDROID HOME   C  Users user name AppData Local Android Sdk in System Variable and  C  Users user name AppData Local Android Sdk platform-tools path in System Variable  replace sharedBlacklist as below code segment   var sharedBlacklist        node modules      react      dist              website  node modules          heapCapture  bundle  js            tests             in node modules metro-config src default blacklist js  Then run npx react-native run-android --port 9001  Happy Coding

User · Answer

You can try the following   Add this line on your AndroidManifest xml   lt application       android usesCleartextTraffic  true    gt         lt  application gt

User · Answer

Try the following    Remove Android and IOS folders run react-native eject run react-native run-android   Maybe after the previous steps you have executions npm start - --reset-cache  I work  I hope it helps you

User · Answer

These steps really help me  Step 1  Create a directory in android app src main assets Linux command  mkdir android app src main assets Step 2  Rename index android js  in root directory  to index js  Maybe there is an index js file in which case you do not need to rename it  then run the following command  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  Step 3  Build your APK  react-native run-android Please use index js in latest version  Enjoy

User · Answer

My solution to this is as below   Start Metro server    react-native start   Start Android    react-native run-android   If see errors saying  port 8081 already in use   then you can kill that process and rerun     react-native start   See  React Native Troubleshooting Page

User · Answer

If you are running on Linux OS there might be case where your npm remote server is not running  Open another terminal  with project directory  and run this command sudo npm start or sudo react-native start before doing sudo react-native run-android

User · Answer

This worked for me after trying several ways    In the file node modules metro-config src defaults blacklist js  Replace     var sharedBlacklist        node modules     react     dist             website  node modules          heapCapture  bundle  js            tests             with     var sharedBlacklist        node modules      react      dist              website  node modules          heapCapture  bundle  js            tests             hope this helps

User · Answer

I have run into similar issue  npx react-native init creates  gitignore file which ignores  lt project gt  android app src debug folder  If you have later cloned this project  this folder would be missing  The solution is simple  In future add this line to the bottom of the  gitignore file   android app src debug For your current project ask the project creator to commit this folder  I have encountered this error with react native version 0 63

User · Answer

IMPORTANT - You might have many Virtual devices in your environment  Ensure if you are changing AVD you repeat the setting again   DEBUG INFORMATION-  Incase you are experiencing above error you have to 1st verify what is running on port 8081  Quickest way to find that is using the following command in terminal  netstat -aon   findstr 8081   if that shows you something it means the port is blocked  if possible get that port unblocked   Otherwise  you would need to change the port  The process to do that has already been mentioned in the comment above by Naveen Kumar  react-native run-android --port 9001   Ensure 9001 is not used either

User · Answer

I was having the same trouble  the problem for me was that adb was not in the right environment path  the error is telling you metro port  while you re in the adb  ports are killed and restarted   Add Enviroment Variable  ADB    Open environment variables Select from the second frame PATH variable and click edit option below Click on add option Submit the sdk platform tools path C  Users  My User  AppData Local Android Sdk platform-tools        Note  Or depending where is located adb exe in your machine    Save changes   Run android build again    react-native run-android     Or      react-native start        react-native run-android

User · Answer

The solution that worked for me is the following   var sharedBlacklist        node modules      react      dist              website  node modules          heapCapture  bundle  js            tests

User · Answer

I m sure it some combination of the other things mentioned here like allowing clear text  which I enabled for localhost  But this was the final piece in the puzzle   project ext react         entryFile   index js           ADD THESE THREE      bundleAssetName   index android bundle       bundleInDebug  true      bundleInRelease  true     RN  0 61 3

User · Answer

you can also downgrade node js to version less than 12 and remove nodemodule then run npm install again

User · Answer

For me this error was caused by an upgrade of react-native     Starting with Android 9 0  API level 28   cleartext support is disabled by default    If you check out the upgrade diff you need to create a debug manifest  android app src debug AndroidManifest xml   lt  xml version  1 0  encoding  utf-8   gt   lt manifest xmlns android  http   schemas android com apk res android      xmlns tools  http   schemas android com tools  gt       lt uses-permission android name  android permission SYSTEM ALERT WINDOW   gt       lt application android usesCleartextTraffic  true  tools targetApi  28  tools ignore  GoogleAppIndexingWarning    gt   lt  manifest gt    See for more info  https   stackoverflow com a 50834600 1713216  https   react-native-community github io upgrade-helper

User · Answer

I did  react-native start  and npx react-native run-android   However  for Min19   Ubuntu based  I was having the same problem until I run   echo fs inotify max user watches 582222   sudo tee -a  etc sysctl conf  amp  amp  sudo sysctl -p   From  https   reactnative dev docs troubleshooting content  At least I got the app running in my cell phone

User · Answer

Starting with Android 9 0  API level 28   cleartext support is disabled by default   This is what you need to do to get rid of this problem if you do normal run commands properly   npm install react-native start react-native run-android   And modify your android manifest file like this        lt application     android name   MainApplication      android icon   mipmap ic launcher      android usesCleartextTraffic  true     add this line with TRUE Value  android theme   style AppTheme  gt

User · Answer

In my case I just close the app form emulator  Then run this again    react-native run-android

User · Answer

Here how I solved this issue without touching the build  1- Closed the Virtual Device 2- Tested on Physical Device -- it works  3- Created new Virtual Device with API 30 Android 10  4- Try again on newly created Virtual Device  and all work like a charm

User · Answer

In Some Cases You Might Want To Close the port Of React-native bundler  and Rerun the App With the same process  1 sudo kill -9   sudo lsof -t -i 9001   2 npm start inside the project  3  react-native run-android

User · Answer

A similar issue happened with me  Apparently Mcafee blocks 8081 port  Took me hours to figure this out   Try running   react-native run-android --port 1234   When app shows up with an error on emulator  get into dev settings  Ctrl M    Change the  Debug server host and port for device  to  localhost 1234    Close the app and start it from the app drawer

User · Answer

By default a tiny JavaScript server called  Metro Server  runs on the port 8081    You need to make this port available for this Server to start  So     release the port close your virtual device   react-native run-android  again     How to release the port    http   tenbull blogspot com 2019 05 how-to-kill-process-currently-using html  How to kill the process currently using a port on localhost in windows   and most importantly  I upgraded my node version from 8 x to 10 x latest   as suggested by facebook    https   facebook github io react-native docs getting-started

User · Answer

I had the same issue  But this method solved it  Go to the android folder using cd android then gradlew clean or   gradlew clean whichever works for your os

User · Answer

I just want to add a non-obvious possibility not covered here  I am using  react-native-community netinfo for detecting network changes  primarily network state  To test network-off state  the WIFI switch  on the emulator  needs to be switched off  This also effectively cuts off the bridge between the emulator and the debug environment  I had not re-enabled WIFI after my tests since i was away from the computer and promptly forgot about it when i got back   There is a possibility that this could be the case for somebody else as well and worth checking before taking any other drastic steps

User · Answer

First do steps 4 and 5 then you can run your project  If you do not get the result  with steps 4 and 5  do the following steps   1- Try to downgrade your Node version  current version is 12 13 1     choco uninstall nodejs   choco install nodejs --version 12 8   2- Add the path of npm module  C  Users your user name AppData Roaming npm  to system variables instead of user variables  3- Install react native globally by using command    npm install -g react-native-cli   4- Go to the root of your project directory and run the following command      react-native start   5- Open another terminal in the root of your project and run the following command       react-native run-android    EDIT    You are using Genymotion    If yes  do the following step     After above step if you get the following error    error Failed to launch emulator  Reason  No emulators found as an output of  emulator -list-avds     Open your genymotion and go to    genymotion menu -  Settings -  ADB -   Then select use custom android sdk tools  click on browse to find sdk location   Finally   run you project again

User · Answer

You haven t started the bundler yet  Run npm start or react-native start in the root directory of your project before react-native run-android

User · Answer

just add three splash in   node modules metro-config src defaults blacklist js  replace this part   var sharedBlacklist        node modules      react      dist              website  node modules          heapCapture  bundle  js            tests

User · Answer

What worked for me was    close all consoles open a new console   adb devices make sure you got only one devices connected   react-native run-android

User · Answer

Try These steps if you have tried everything mentioned in above solutions    Create File in android app src main assets Run the following command         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    Now run your command to build for e g  react-native run-android

User · Answer

After hours searching for a answer  The solution was to make a downgrade node to version 12 4   In my case I realize that the error just occurs in version react native 0 60 with node version 12 6

User · Answer

Hey guys a combination of 2 awnsers solved my problem  It was port related  adb reverse tcp 8088 tcp 8088 react-native run-android --port 8088  By doing this  the app loaded fine of my phone connected by USB  I think my AV or Vagrant or something elses in my PC was using that port  You can change 8088 to something else if needed  Enjoy

User · Answer

I ve encountered the same issue while following the React Native tutorial  developing on Linux and targeting Android    This issue helped me resolve the problem in following steps  Run following commands in the below sequence     in project directory  mkdir android app src main assets 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 react-native run-android   You can automate the above steps by placing them in scripts part of package json like this    android-linux    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  amp  amp  react-native run-android    Then you can just execute npm run android-linux from your command line every time

[reactjs] Unable to load script.Make sure you are either running a Metro server or that your bundle 'index.android.bundle' is packaged correctly for release

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