React-Native: Application has not been registered error
JavascriptFacebookReactjsReact NativeJavascript Problem Overview
I am currently going through the React-Native tutorials. I began with the Getting Started tutorial, where I made a new react native project and successfully managed to run the project on my device.
I then started the Props tutorial, I copied the code snippet and tried to run the project again and had the following error message show up on my screen:
Javascript Solutions
Solution 1 - Javascript
I guess it is an error caused by not matching name of project and your registered component.
You have inited project with one name, i.e.
react-native init AwesomeApp
But in your index.ios.js file you register other component
AppRegistry.registerComponent('Bananas', () => Bananas);
When it must be
AppRegistry.registerComponent('AwesomeApp', () => Bananas);
If your component name does match, ensure you don't have any other react-native/node process running in another terminal.
Solution 2 - Javascript
Most of the times the problem is that you have another react-native start
(i.e. React Native Packager) server running either on another terminal or another tab of TMUX (if you are using TMUX).
You need to find that process and close it, so after running react-native run-ios
for instance, it will establish a new packager server that registered for that specific application.
Just find that process using:
ps aux | grep react-native
find the process id (PID) and kill the packager process using kill
command (e.g. kill -9 [PID]
). You should find the launchPackager.command
app in macOS, not sure about the other operating systems.
Then try to run the run-ios
(or android) again. You should be able to see the new path after running the new packager server, e.g.:
Looking for JS files in
/Users/afshin/Desktop/awesome-app
Solution 3 - Javascript
Modify MainActivity
in android/app/src/main/java/com/your-package-name/MainActivity.java
like this,
@Override
protected String getMainComponentName() {
return "Bananas"; // here
}
Solution 4 - Javascript
My solution is change module name in "AppDelegate.m"
from
moduleName:@"AwesomeProject"
to
moduleName:@"YourNewProjectName"
Solution 5 - Javascript
First of all you must start your application:
react-native start
Then, you must set your application name as the first argument of registerComponent.
It works fine.
AppRegistry.registerComponent('YourProjectName', () => YourComponentName);
Solution 6 - Javascript
In my case there's this line in MainActivity.java which was missed when I used react-native-rename
cli (from NPM)
protected String getMainComponentName() {
return "AwesomeApp";
}
Obviously ya gotta rename it to your app's name.
Solution 7 - Javascript
Please check your app.json file in project. if there has not line appKey then you must add it
{
"expo": {
"sdkVersion": "27.0.0",
"appKey": "mydojo"
},
"name": "mydojo",
"displayName": "mydojo"
}
Solution 8 - Javascript
I resolved this by changing the following in the app.json file. It appears the capital letter was throwing this error.
From:
{
"name": "Nameofmyapp",
...
}
To:
{
"name": "nameofmyapp",
...
}
Solution 9 - Javascript
In index.js you have the following code:-
import {name as appName} from './app.json';
AppRegistry.registerComponent(appName, () => MyApp);
So if in app.json, name is defined as "AwesomeProject" then make sure it same as the following:-
-
moduleName in ios/projectName/AppDelegate.m :-
moduleName:@"AwesomeProject"
-
component name in android/app/src/main/java/MainActivity.java
@Override
protected String getMainComponentName() {
return "AwesomeProject"; // here
}
Solution 10 - Javascript
I think the node server is running from another folder. So kill it and run in the current folder.
Find running node server:-
lsof -i :8081
Kill running node server :-
kill -9 <PID>
Eg:-
kill -9 1653
Start node server from current react native folder:-
react-native run-android
Solution 11 - Javascript
I had the same problem and for me the root cause was that I ran (react-native start) the packager from another react-native folder (AwesomeApp), while I created another project in an other folder.
Running the packager from the new app's directory solved it.
Solution 12 - Javascript
This solution worked for me after 2 days of debugging. Change this :
AppRegistry.registerComponent('AppName', () => App);
to
AppRegistry.registerComponent('main', () => App);
Solution 13 - Javascript
For me the issue was simple.
Created project a -> everything worked
Created project b -> ran into this error
metro was still running with the work path set to the other application. In my case the solution was as simple as closing the metro process and let it restart
Solution 14 - Javascript
you need to register it in index.android.js / index.ios.js
like this:
'use strict';
import {
AppRegistry
} from 'react-native';
import app from "./app";
AppRegistry.registerComponent('test', () => app);
Solution 15 - Javascript
This can also be due to Root component name starts with lowercase.
Recorrect it or rather create the project once again with a PascalCase name.
e.g. ignite new HelloWord
Solution 16 - Javascript
All the given answers did not work for me.
I had another node process running in another terminal, i closed that command terminal and everything worked as expected.
Solution 17 - Javascript
This solved it for me
AppRegistry.registerComponent('main', () => App);
So my index.js
file
import { AppRegistry } from 'react-native';
import App from './App';
AppRegistry.registerComponent('main', () => App);
And my package.json
file:
"dependencies": {
"react": "^16.13.1",
"react-dom": "~16.9.0",
"react-native": "~0.61.5"
},
Solution 18 - Javascript
Rather than changing the name in AppRegistry
,
Run react-native init Bananas , this will create react boilerplate code for Bananas project and AppRegistry.registerComponent
will automatically point to bananas
AppRegistry.registerComponent('Bananas', () => Bananas);
Solution 19 - Javascript
Non of the solutions worked for me. I had to kill the following process and re ran react-native run-android and it worked.
node ./local-cli/cli.js start
Solution 20 - Javascript
I had the same problem. I was using Windows for creating a react native app for android and was having the same error. Here's what worked.
- Navigate to the folder ANDROID in your root.
- Create a file with name : local.properties
- Open it in editor and write :
> sdk.dir = C:\Users\ USERNAME \AppData\Local\Android\sdk
- Replace USERNAME with the name of your machine.
Save and run the app normally. That worked for me.
Solution 21 - Javascript
The issue will also appear when, in index.js, you have named the app differently from the name you gave it for the android/ios package; probably this happened when you've ejected the app. So be sure that when calling AppRegistry.registerComponent('someappname', () => App)
, someappname is also used for the native packages or viceversa.
Solution 22 - Javascript
I figured out where the problem was in my case (Windows 10 OS), but It might also help in Linux as well( You might try).
In windows power shell
, when you want to run an app(first time after pc boot) by executing the following command,
react-native run-android
It starts a node process/JS server
in another console panel
, and you don't encounter this error. But, when you want to run another app, you must need to close that already running JS server console panel
. And then execute the same command for another app from the power shell
, that command will automatically start another new JS server for this app, and you won't encounter this error.
You don't need to close and reopen power shell
for running another app, you need to close node console
to run another app.
Solution 23 - Javascript
After have read all the above, I have found that there could be another reason for this.
In my case:
react-native-cli: 2.0.1
react-native: 0.60.4
and following structure:
First has to be noted that index.android is not been update in Android Studio when the build run by Metro builder( react-native run-android) so it has to be done manually. Also in Android studio does not "read" the
app.json(created by default together with index.js, that renamed index.android.js):
{
"name": "authApp",
"displayName": "authApp"
}
and so this like
(in my case)
import {authApp as appName} from './app.json';
cause the fact that android studio does not know what authApp refer to. I fix for the moment referring to the app name with its string name and not using that import from app.json:
AppRegistry.registerComponent('authApp', () => MyApp);
Solution 24 - Javascript
My issue was that in AndroidManifest.xml
and MainActivity.java
package names were different. So in manifest I had package=com.companyName.appName
and in activity package com.appName
Solution 25 - Javascript
In my case i have got a different solution in case any one need
yarn remove react-native-material-dropdown
Install new packages react-native-material-dropdown-v2
yarn add react-native-material-dropdown-v2
Replace react-native-material-dropdown with react-native-material-dropdown-v2 in your code
> e.g. import { Dropdown } from 'react-native-material-dropdown' to > import { Dropdown } from 'react-native-material-dropdown-v2'
another thing ==========
- Open node_modules and then search for react-native-material-textfield open the file and go to src folder
- Under src you will see affix, helper, label folder - under each folder, there is an index.js
- open the index.js of the mentioned folders one by one (all 3 folders) and search for the text style: Animated.Text.propTypes.style, and replace it by style: Text.propTypes
- And import text form react-native like this import { Animated , Text} from 'react-native';
Solution 26 - Javascript
If you are with expo, you should not change the moduleName in AppDelegate.m and in getMainComponentName(), the default name by registerRootComponent(App) is "main", so it should be remain "main"
Solution 27 - Javascript
change name and displayname property in app.json with newer name