Could not connect to development server on android emulator

Issue

When i run a react native simple app using command.react-native run-android.Then i got an error "could not connect to a development server, although my packager is also run.

Solution

There is a few things you can try to solve this.

From the React Native official docs (https://facebook.github.io/react-native/docs/troubleshooting) you could try to "terminate the process on port 8081" by running:

$ sudo lsof -i :8081
$ kill -9 <PID>

You will run the second command on all PIDs that are using port 8081 (this will terminate your emulator too).

Then, restart the emulator and in one terminal, run:

$ npm start

and on a second terminal:

$ react-native run-android

Hope this can help!

Answered By - perotta