Troubleshooting

1. APK Not Reloading from Metro Bundler

When we install a debug APK on a physical device via USB and the app fails to connect to the Metro bundler (no live reload, no fast refresh, "Unable to load script" error), it usually means the app on the device can't reach the Metro server running on our laptop.

Even if adb devices shows our device, the network bridge between the app and Metro must be explicitly established.

Prerequisites

Before troubleshooting, make sure:

1. Metro bundler is running.
2. The device is connected via USB and USB debugging is enabled.
3. adb devices lists our device as device.
4. We have installed a debug APK, not a release build. Debugging features (Metro reload, Fast Refresh, Dev Menu) only work in debug builds.

Fix

1. When single device is connected

adb reverse tcp:8081 tcp:8081

2. When multiple devices are connected

adb -s <device_id> reverse tcp:8081 tcp:8081