Question: I have basic `React Native` app. I am trying to test it in virtual Android device. I am navigating to the project and type `npm start -- --reset-cache`. I kill the proccess and I am typing `react-native run-android`. I have active Android device, but I see on it this error:

> 
> The development server returned response error code: 404
>  URL: <http://10.0.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false>
>  Body... "Cannot find entry file index.js in any of the roots:[\"c:\\projects\\HelloRN]"....
> 
> 
> 

I have index.js in the root of the project. Metro Bundler is running on port 8081, but I see same error from it.
I am using `React Native 0.51.0`.

Answer: 
There are two possible solutions:

1. index.js file isn't in the project root
2. react-native, in some cases, can't read index.js because try to find index.ios.js and index.android.js, so, duplicate index.js and rename to index.android and index.ios.js
The problem was with permissions. When I create same project in another partition, but not in the `C:` partition, where `Windows` is installed, it works fine and it founds `index.js` file.