error "Could not get BatchedBridge, make sure your bundle is packaged properly" on start of app

A possible solution for this is that you most probably not bundling your application first, perform the following steps and then deploy your app-debug.apk to your device

$ cd myproject  
$ react-native start > /dev/null 2>&1 &  
$ curl "http://localhost:8081/index.android.bundle?platform=android" -o "android/app/src/main/assets/index.android.bundle"

(if the folder assets does not exists create it)

Then run from project root

$> (cd android/ && ./gradlew assembleDebug)

install the created apk to you device, from location: android/app/build/outputs/apk/app-debug.apk

let me know if that fixes your issue

EDIT:

You can simply put it to your package.json as a script to automate it, I believe it will be fixed in upcoming releases of react-native and will be executed prior assembling the final APK, hence this won't be needed (I hope as well)

put :

"scripts": {
    "build": "(cd android/ && ./gradlew assembleDebug)",
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "bundle-android": "react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --sourcemap-output android/app/src/main/assets/index.android.map --assets-dest android/app/src/main/res/"
  },

or as mentioned the curl equivalent, but for most cases the above is more robust

I came across this issue as well. What I did was force kill the app on my device, then I opened up another console and ran

react-native start

and then I opened the app again from my device and it started working again.

EDIT: If you are using an android device via USB and have unplugged it or your computer went to sleep, you may have to first run

adb reverse tcp:8081 tcp:8081

Just got this error. Here's what I did to fix: I selected Dismiss, Went into the Developer menu, then Dev Settings, Choose Debug server host & port for device, I added my computers IP address and the port: 192.168.0.xx:8xxx, use whatever your developer machines assigned IP address is on your wifi network. The port is usually :8081

Once I did this, all went well. Also, while you're in the dev menu remember to select Enable Live Reload and Debug JS Remotely, it makes your life much-much easier while debugging.