So this has been asked before but I'm asking it again because nothing has worked, I've read through all of the similar posts I could find and all but one has semi fixed the problem.
https://medium.com/#adityasingh_32512/solved-unable-to-load-script-from-assets-index-android-bundle-bdc5e3a3d5ff
This medium article is the only solution that i can find that will get debug builds running again but that is only because it is pre packaging the javascript bundle and not really fixing the problem of the app not connecting to the metro server, once the debug build is running via this method I'm unable to shake the device and get the debug menu to show up.
I've been developing this app for probably 10 months, live for 3-4 months, and can usually trudge through these errors that pop up but this one is tricky.
I've been using cleartextTrafficPermitted="true", tried implementing a custom network security config android:networkSecurityConfig="#xml/network_security_config", tried a different physical device, cleared the metro cache, deleted .gradle/ build folders, cleaned, rebuilt.. All with the same end result of the app crashing on boot and the same error in logcat Unable to load script. Make sure you're either running a Metro server (run 'react-native start') or that your bundle 'index.android.bundle' is packaged correctly for release.
Release builds work but that's because its not trying to connect to the metro server, pretty stumped on this one.
Answering this for others that might find it useful. Still not sure what I did wrong but in the process of setting up a CI/CD pipeline for the app I re cloned the project and magically android debug builds started working again. No changes to the code, the android project must have gotten corrupted somehow so recloning allowed android studio to start from square one. Weird one.
I upgraded a react native project recently from expo SDK 36 to 38. It compiles now, but anytime I click on "Debug Remote JS", it causes the UI to become slow and unresponsive, only occasionally picking up the on click events. I created a bare bones project to duplicate it. To verify, either run expo init from cli or here's a project https://github.com/seniordevops/tab-application.git. Click the tabs without the debugger on, then turn on debug remote JS and watch the slow down. Happens on both Mac and PC. Any ideas on the root cause?
This is mostly due to the fact that the clock on your PC and mobile are not synchronized.
You either have to synchronize them or have the phone clock one second earlier than your PC/Mac.
I suspect the reason could be an upstream problem of react-native. Please check this expo-cli issue:
https://github.com/expo/expo-cli/issues/2405
a maintainer reports:
when you are debugging on your device, the javascript is being
executed in your browser on your computer :(
React Native app debug on real device has some problems;
My metro bundler console gives warn:
warn No apps connected. Sending "reload" to all React Native apps failed. Make sure your app is running in the simulator or on a phone connected via USB.
warning and that cause real IOS device connection problem.
When I try to reload my react native app from Chrome React Native Debugger, it gives above warning and I can not debug my code from on Chrome
react-native: 0.62.2,
IOS: 13.6
It happens on Real device connection. When I work with IOS simulator, there is not problem.
NOTE: My phone and macbook on SAME wi-fi network.
So problem is not related to different wi-fi network usage.
⚠️ For iOS users :
Check that your build target is Debug :
Xcode Product => Scheme => Edit Scheme => Debug (and not release ! )
⚠️ For Android users :
I have found a solution that I posted on github.
Not the best but it could be useful:
First, you have to open MainApplication.java
and remove import com.facebook.react.BuildConfig;
Next, follow these steps :
# Reset metro bundler cache :
`npx react-native start --reset-cache`
# Remove Android assets cache :
`cd android && ./gradlew clean`
# Relaunch metro server :
`npx react-native run-android`
And see the magic 🎉
See here :
https://github.com/facebook/react-native/issues/29396
Running this worked for me for a Physical Android Device.
adb reverse tcp:8081 tcp:8081
or
npm run android-connect
If you face an error saying 'More than two devices are running', make sure that the emulators like BlueStacks are not running.
Your iPhone has to be connected to the same network (WiFi for example) as your Mac, because they have to communicate with each other (React Native Doc).
If it's already the case, then fill in the DCHP server manually on your iPhone and Mac, using Google's server (8.8.8.8), because it could be due to DHCP problems.
You may need to disconnect and reconnect to your Wifi.
For me I need to set the bundler location in my app from "localhost:8081" to "192.168.1.XX:8081" which is my computer's local IP address where Metro bundler runs on and the port is 8081.
If you don't know which port your bundler runs on you can specify it as a parameter like:
npx react-native start --port 8081
Then you need to specify the location in your development app. To do that:
Shake your device
Click change bundle location (I am on RN 0.64 it may differ in yours)
Give the bundler location of your computer's IP and port where Metro bundler runs on like:
and they started to communicate with each other.
My problem was that I was not connected to the same WiFi on my Mac and Iphone.I turned the wifi off and back on on both devices, and made sure both the mac and Iphone was connected to the same WiFi. Annoying, but true!
Your iPhone & mac must be connected to the same network. If both device connected to same network you must check local network availability for your app. (this happened to me on a iOS 14.0 running device).
check local network - iOS 14
Settings -> Privacy -> Local Network
On Android, this may also happen due to a problem with the network security config. If you do use the network security config, try removing the line android:networkSecurityConfig="#xml/network_security_config" from AndroidManifest.xml
My problem was that the emulator I was using had airplane mode turned on (because I tested related functionality). The problem resolved when I turned it off, thus enabling network to operate as usual.
My problem is that the device is not connected to the internet. Throws the error. Try connecting stable internet connection.
When I remove network_security_config.xml and remove the following:
`android:networkSecurityConfig="#xml/network_security_config"`
It works
I work on IOS environment, testing on an IPad that is USB connected.
I managed to fix this issue by adding the bundler address (127.0.0.1) in the ipad to reconnect
Shake the device (opens react native debug menu) > Configure Bundler > "127.0.0.1" in the first field
Hope this helps someone !
What did the trick for me was the following:
In Xcode go to Debug/Detach from YourAppName
Then reattach it by going to Debug/Attach to Process, select your app from the list (usually the first entry at the top).
I tried everything and after running
adb reverse tcp:8081 tcp:8081
yarn android
it worked.
What worked for me in this scenario was these steps
run server with --reset-cache
run npx jetify
open the project in adroid studio
go to refactor -> Migrate to AndroidX (this was the step that i was missing earlier)
start your emulator
run the app from android studio and it should work
Sometimes it's a firewall / router issue - see if that's your problem:
Find out the local IP address of your computer (where your Metro bundler / server is running).
Open a browser from your phone.
Open the IP address from #1 with port 8081 (e.g. http://192.168.0.42:8081).
If it's not loading -> it's a firewall / router issue.
A simple solution would be to connect the computer to the phone's hotspot.
yarn start web
you can use this command to scan the QR code and see the app in you EXPO app at you mobile
You musk permit local network in the application setting in iOS. Otherwise, Metro can not find your app even in the same network.
For iOS on Xcode:
Go to Window > Devices and Simulators, Go to "Installed Apps" section, Click on +, Pick your app , Run your code.
(This issue happened to me when I run the app after I uninstalled it from the device)
For me the solution was to remove the installed app and build run in Xcode again.
Oh, I had the same problem with RN - for me - there was a problem with connecting iphone to macbook server on localhost - and it solved if I just turned off wifi on macbook and then turned it on again. (Yes, it sounds weird - but it's a common problem)
For me, on IOS, Xcode would be stuck in debugging, a breakpoint is active and Metro can't reload because no apps are connected. To solve this:
open Xcode
In the left-hand side panel, click from the top row on Debug navigator (if it's not already focused and in the view like it was for me)
In the bottom pane (which can be minimized fully, in which case you have to hold and drag from the bottom of Xcode to expand it into view) you see a set of debugging buttons, the most left
one is a blue arrow-head-shaped button that continues/unpauses the script, click it.
after unpausing the script my app would connect to Metro.
Easy solution ->
1- Go to Developer options of your phone .
2- Disable adb authorization timeout..
Now reload project and enjoy coding..
My problem was that i added --variant=release
npx react-native run-android --variant=release
So i remove it and worked for me.Like this:
npx react-native run-android
Recently I switched from Ionic framework to vue-native (vue.js wrapper around react-native), everything seems to be cool, development is fast and easy, but I have some real issues with debugging those apps. With Ionic Framework (Cordova) I was able to open an app in web browser and could easily manage Vuex state (for example) from Chrome Console. It doesn't seems so easy and trivial in react native world. Is it possible to have similar debugging experience in vue-native? When my app starts to grow and gets complicated it's really hard to handle it other way around. Any help appreciated.
Basically all my problems gone away when I ported my apps to Expo (which allows for JS remote debugging) and grabbed React Native Debugger - https://github.com/jhen0409/react-native-debugger.
Important part is having simulator installed on your developer machine (like iphone simulator) because debugger doesn't play nicely with real machines.
Inside debugger hit cmd+t to open a new window and set port to 19001 (because of Expo using this port). Now start expo with npm start command and in Expo panel hit 'Run in simulator' button.
In simulator make a shake gesture (ctrl+cmd+z) and allow remote debugging in developer menu.
Done. Pleasant experience similar to one known from Cordova. You have a js console, you can inspect elements and change styles live. Expo comes with live reload to make things smoother.
More info here: https://docs.expo.io/versions/latest/workflow/debugging/
Unfortunately, you cannot debug script parts in the VUE files in Chrome Dev Tools (you can put the breakpoints, but they are not working well), but if you put the methods to a separate JS file, it works like a charm. I know, it's a workaround, but not a big pain, and working well.
See my TODO app for example: https://github.com/TheBojda/VueNativeTodo
Appreciate your lecture.
Currently, I can successfully deploy the app onto my iPhone device.
However, the app is rely on local-dev-server.
How could I get rid of the local-dev-server?
I used this command to deploy the app react-native run-ios --device 'iPhone' onto my cellphone
Here's my repo
https://github.com/poc7667/reacti-native-album
Here is a section from RN docs:
Building an app for distribution in the App Store requires using the Release scheme in Xcode. Apps built for Release will automatically disable the in-app Developer menu, which will prevent your users from inadvertently accessing the menu in production. It will also bundle the JavaScript locally, so you can put the app on a device and test whilst not connected to the computer.
To configure your app to be built using the Release scheme, go to Product → Scheme → Edit Scheme. Select the Run tab in the sidebar, then set the Build Configuration dropdown to Release.
you just need to select the Release scheme on the run configuration in xCode and hit the run button.