Could not connect to development server on android emulator and on real device
Problem
Is this a bug report? Its an issue i am facing while running the normal Awesome Project on my system Have you read the Contributing Guidelines? Yes Environment 1. `react-native -v`: 0.47.1 2. `node -v`:8.2.1 3. `npm -v`:4.1.2 4. `yarn --version`: Then, specify: - Target Platform: Android - Development Operating System: Windows 7 - Build tools:26.0.0-rc2 Steps to Reproduce (Write your steps here:) 1.Open command prompt in Administrator Mode 2.run command: cd <directory where i want to create the project> 3.run command: react-native init <project name> 4.run command: cd <project name> 5.run command: react-native run-android this makes the package server run automatically on port 8081. But I am not able to access the package server from browser on the machine and the mobile. I tried using http://<system ip>:port/index.android.js http://localhost:port http://127.0.0.1:port => I was getting the red screen on both mobile and the emulator with following message: I tried running the project on real device and on emulator. On Both I got error: "Unable to load script from assets 'index.android.bundle' Make sure your bundle is packaged correctly or you're running a package server'. reloading i get the error: "Could not connect to development server." Then i set the host and port number on development setting on both and got the error "Could not connect to development server." Expected Behavior The project is expected to run on emulator and phone without any error. Bu
Error Output
error: "Unable to load script from assets 'index.android.bundle' Make sure your bundle is packaged correctly or you're running a package server'.
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1 Fix
Fix Connection Issues to Development Server in React Native
The error occurs because the React Native packager is not accessible from the emulator or the real device. This can happen due to incorrect IP address configuration, firewall settings, or network issues preventing the device from accessing the development server running on the host machine.
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- 1
Check Local IP Address
Ensure you are using the correct local IP address of your development machine. You can find this by running 'ipconfig' in the command prompt and looking for the IPv4 address.
bashipconfig - 2
Update React Native Debug Settings
On your emulator or real device, shake the device or press 'Ctrl + M' to open the developer menu. Select 'Dev Settings' and then 'Debug server host for device for the app'. Enter your local IP address followed by ':8081'. Example: '192.168.1.100:8081'.
- 3
Disable Firewall Temporarily
Sometimes, the firewall can block connections to the development server. Temporarily disable the firewall on your Windows machine to see if it resolves the issue. Make sure to re-enable it after testing.
- 4
Run React Native Packager Manually
Open a new command prompt and navigate to your project directory. Run the React Native packager manually to ensure it is running properly. Use the command 'react-native start'.
bashcd <project name> && react-native start - 5
Rebuild the Project
After making the above changes, rebuild the project by running 'react-native run-android' again to ensure all configurations are applied.
bashreact-native run-android
Validation
To confirm the fix worked, check if the app loads without errors on both the emulator and the real device. You should see the application running without the 'Unable to load script from assets' error. Additionally, you should be able to access the packager in your browser using http://<local-ip>:8081.
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Environment
Submitted by
Alex Chen
2450 rep