JS server not recognized, continuing with build

Question

Environment

Windows 10

Npm 5.5.1

react-native-cli 2.0.1

react-native 0.50.3

Genymotion Google Nexus 7 - 6.0.0 API 23

Answer 1

Steps that helped me in similar case:

1. Running packager on port different than 8081: react-native start --port 8082 --reset-cache
2. Running command react-native run-android --port 8082 in second Command Prompt window.
3. After error screen appear clicking Ctrl + M.
4. Clicking Dev Settings button at the bottom.
5. Clicking Debug server host & port for device button.
6. Writing localhost:8082 and clicking OK button.
7. Again running command react-native run-android --port 8082