React-Native: Application has not been registered error

Question

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 t

Answer 1

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

Answer 2

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",
  ...
}

Answer 3

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.

Answer 4

This solution worked for me after 2 days of debugging. Change this :

AppRegistry.registerComponent('AppName', () => App);

to

AppRegistry.registerComponent('main', () => App);

Answer 5

My solution is change module name in "AppDelegate.m"

from moduleName:@"AwesomeProject"

to moduleName:@"YourNewProjectName"

Answer 6

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"
}