Error type 3. Activity class {com.awesome_project/ com.awesome_project.MainActivity} does not exist in react native (Android device)

I've created the project using the following command.

react-native init Awesome_Project

I've started the packager using the following command.

react-native start

I've connected my Android mobile using USB drive.

I've opened another command prompt and run the following adb command to make sure that only one device is connected.

adb devices

I've started the application using the following command.

react-native run-android

I've been confronted with the following error.

open: Permission denied
open: Permission denied
Starting: Intent { com.awesome_project/.MainActivity }
Error type 3
Error: Activity class {com.awesome_project/ com.awesome_project.MainActivity} does not exist.

Thanks in advance.

Make sure android/app/build.gradle

defaultConfig {
        applicationId "WHATEVER_THIS_IS" 
}

needs to match android/app/src/main/java/com/app_name/MainActivity.java line one:

package WHATEVER_THIS_IS;

needs to match android/app/src/main/java/com/app_name/MainApplication.java line one:

package WHATEVER_THIS_IS;

needs to match android/app/src/main/AndroidManifest.xml line one:

package="WHATEVER_THIS_IS">

I uninstalled the app from my device and was not able to see it in my Settings > Apps at all. The error finally went away after I fully uninstalled the app by doing:

adb uninstall com.appname

If you have appIdSuffix you should add it to the command for react native run command.

eg.   react-native run-android --appIdSuffix beta

Should add shortcut to package.json and run via npm.

...
"scripts": {
 ...
  "android-beta": "react-native run-android --appIdSuffix beta",
},

Then just run:

npm run android-beta

adb uninstall packageName Worked for me. for eg: adb uninstall com.abc

In my case the app just doesn't open automatically, there's no other issue.

Just search for the app icon in your android device (look at location of all applications) and tap on it to open the app manually. The packager will begin to load the app as usual.

So this seems to be a bug here. Unfortunately I don't really know what's causing it.