No apps connected. Sending "devMenu" to all React Native apps failed - react-native

This is a strange error when I ran React Native (0.63.2) app on Android 8.1 emulator with
npx react-native run-android
Here is the full warning message:
warn No apps connected. Sending "devMenu" to all React Native apps failed. Make sure your app is running in the simulator or on a phone connected via USB.
info Opening developer menu...
Tried adb reverse tcp:8081 tcp:8081 but didn't help. The emulator was working fine. What can go wrong here?

Note: Answer targets only those visitors, who are facing this issue after successfully running once on device
npx react-native run-android
//once its installed on device next time just do
npx react-native start
installs app at your device on first run. I was facing same issue only when I tried npx react-native run-android second time.
So I used npx react-native start then
I just opened my latest app installed by last run and its working and showing me the updates as well

Related

React Native Android App run on emulator doesn't connect to metro bundler when installed using android-studio

My React-Native(0.68.1) project runs properly on my emulator when using npx react-native run-android command and everything works fine with the metro bundler instance created by this command.
Only when I run project from android studio (2021.3.1 Patch 1) , app is build successfully and installed on emulator, but cannot connect to metro bundler (which I separately run using npx react-native start command).
I wanted to try and update the debug server & port as mentioned in other similar questions , but I cannot access the debug app menu even after dismissing the error (menu doesn't show when ipress the shortcut)
Issue also occurs on build installed on emulator via npx react-native run-android when I close the app and metro bundler created by the command and start a separate metro bundler. In this case but I am able to enter settings menu and enter "debug server and port " to 10.0.2.2:8081 and app connects to metro.
I am using mac mini m1.
To fix this issue
first of all, start your emulator and run adb reverse tcp:8081 tcp:8081 this command on the terminal and then run npx react-native start and then run your project in the android studio and it will automatically link your app to that bundle

React-Native Issue while running "npx react-native run-android"

while running npx react-native run-android it shows an error
This issue is happening because you are connected with any Android device or any emulator, to connect with your emulator, you need to add a virtual device, to add a virtual device please follow these links https://developer.android.com/studio/run/managing-avds and https://developers.foxitsoftware.com/kb/article/create-an-emulator-for-testing-in-android-studio/
then run adb devices in your root-project in terminal, you must be able to run the app..

React Native Android Studio Emulator launch issue

When I try to start my react-native init project with this command npx react-native start nothing happens in the emulator.
enter image description here
Command npx react-native start is for starting up the bundler (Metro)
to run it on an android emulator or device you need npx react-native run-android.
Before that please make sure you have either a real device connected or an emulator ready.
You can follow or check by using this guide for your Android environment setup.

react-native run-android error metro server

I'm doing a react-native app.
When I launch my app with react-native start or npm run start and react-native run-android, it install on my phone the app but don't launch it automatically and when I launch it by myself, I have this error :
Can you help me I don't know what is my problem ?
thank
I think your phone and your computer are not connected to the same network

Building and installing the app on the device react-native window and android

I just started with react-native.
But I have a problem with the replay of the project. I use the command react-native run-android, this annoys me an error see capture.
The problem was resolution. I almost opened two console: one I compile with
npm start
and the other run
react-native run-android