Module AppRegistry is not registered callable module (calling runApplication)

Just kill all node process and start npm server and run application:

Step1: run command killall -9 node

For windows users, run: taskkill /im node.exe

Run taskkill /f /im node.exe if the process still persists.

Step2: run command npm start --reset-cache

Step3: run command react-native run-ios OR react-native run-android