Question: I'm new in react-native.
I have run react native project on Ubuntu by using 'react-native run-android' command. And I got the error on emulator 
"Unable to load script from assets 'index.android.bundle'.Make sure your bundle is packaged correctly or you are running a package server."

Answer: 
This helped me resolve the problem in following steps.

* If not than (in project directory) mkdir android/app/src/main/assets
* `react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res`
* `react-native run-android`
I was stuck in the same problem for hours and what solved my issue is this :
Create "assets" folder in main directory of project as well as in "newreactproject\android\app\src\main". Then put this script in package.json `"android-android": "react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res && react-native run-android"`  

like:

```
"name": "newreactproject",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "android-android": "react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res && react-native run-android",
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest"
  }

```