PID: 21144 java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.BinaryMessenger.setMessageHandler on a null object reference

[saravananmnm]

2020-10-29 15:55:04.516 21144-21144/com.courieralliance.driverca.qa E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.courieralliance.driverca.qa, PID: 21144
java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.BinaryMessenger.setMessageHandler(java.lang.String, io.flutter.plugin.common.BinaryMessenger$BinaryMessageHandler)' on a null object reference
at io.flutter.plugin.common.MethodChannel.setMethodCallHandler(MethodChannel.java:116)
at io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin.onAttachedToEngine(FirebaseMessagingPlugin.java:60)
at io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin.registerWith(FirebaseMessagingPlugin.java:51)
at com.courieralliance.driverca.Application.registerWith(Application.java:29)
at com.transistorsoft.flutter.backgroundfetch.HeadlessTask.startBackgroundIsolate(HeadlessTask.java:150)
at com.transistorsoft.flutter.backgroundfetch.HeadlessTask.dispatch(HeadlessTask.java:101)
at com.transistorsoft.flutter.backgroundfetch.HeadlessTask.run(HeadlessTask.java:95)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

[saravananmnm]

When i kill the application by that time this issue occurred.

`

import io.flutter.app.FlutterApplication;
import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin;
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService;
import io.flutter.plugins.sharedpreferences.SharedPreferencesPlugin;
import com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin;
import io.flutter.plugins.pathprovider.PathProviderPlugin;
import com.baseflow.geolocator.GeolocatorPlugin;
import rekab.app.background_locator.LocatorService;
import com.whelksoft.flutter_native_timezone.FlutterNativeTimezonePlugin;
import com.transistorsoft.flutter.backgroundfetch.BackgroundFetchPlugin;

public class Application extends FlutterApplication implements PluginRegistry.PluginRegistrantCallback {

@Override
public void onCreate() {
    super.onCreate();
    FlutterFirebaseMessagingService.setPluginRegistrant(this);
    BackgroundFetchPlugin.setPluginRegistrant(this);
    LocatorService.setPluginRegistrant(this);
}

@Override
public void registerWith(PluginRegistry registry) {
    // I've only had to add this line to make it work
    if (!registry.hasPlugin("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin")) {
        FirebaseMessagingPlugin.registerWith(registry.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
    }
    if (!registry.hasPlugin("com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin")) {
        FlutterLocalNotificationsPlugin.registerWith(registry.registrarFor("com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin"));
    }
    if (!registry.hasPlugin("com.transistorsoft.flutter.backgroundfetch.BackgroundFetchPlugin")) {
        BackgroundFetchPlugin.registerWith(registry.registrarFor("com.transistorsoft.flutter.backgroundfetch.BackgroundFetchPlugin"));
    }

    if (!registry.hasPlugin("io.flutter.plugins.pathprovider")) {
        PathProviderPlugin.registerWith(registry.registrarFor("io.flutter.plugins.pathprovider"));
    }
    if (!registry.hasPlugin("io.flutter.plugins.sharedpreferences")) {
        SharedPreferencesPlugin.registerWith(registry.registrarFor("io.flutter.plugins.sharedpreferences"));
    }
    if (!registry.hasPlugin("com.whelksoft.flutter_native_timezone")) {
        FlutterNativeTimezonePlugin.registerWith(registry.registrarFor("com.whelksoft.flutter_native_timezone"));
    }
    if (!registry.hasPlugin("com.baseflow.geolocator.GeolocatorPlugin")) {
        GeolocatorPlugin.registerWith(registry.registrarFor("com.baseflow.geolocator.GeolocatorPlugin"));
    }

}

}
`

[darshankawar]

@saravananmnm
Is this an issue with Firebase plugin ? I can't seem to understand what exactly your issue is. You seem to have lot of 3rd party plugins in above comment.
Please provide flutter doctor -v and minimal code sample that shows the issue you are facing.

[saravananmnm]

Yes @darshankawar.
i think this is a Backward compatibility issue with plugins (v1).

C:\Saravanan\Flutter_Sdk\flutter\bin\flutter.bat doctor --verbose
[√] Flutter (Channel stable, 1.22.1, on Microsoft Windows [Version 10.0.18362.1082], locale en-IN)
• Flutter version 1.22.1 at C:\Saravanan\Flutter_Sdk\flutter
• Framework revision f30b7f4db9 (3 weeks ago), 2020-10-08 10:06:30 -0700
• Engine revision 75bef9f6c8
• Dart version 2.10.1

[√] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
• Android SDK at C:\Users\Admin\AppData\Local\Android\sdk
• Platform android-30, build-tools 30.0.0
• Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
• All Android licenses accepted.

[√] Android Studio (version 4.0)
• Android Studio at C:\Program Files\Android\Android Studio
• Flutter plugin version 50.0.1
• Dart plugin version 193.7547
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)

[√] Connected device (1 available)
• Android SDK built for x86 (mobile) • emulator-5554 • android-x86 • Android 10 (API 29) (emulator)

• No issues found!
Process finished with exit code 0

[darshankawar]

@saravananmnm
Please use the issue template and provide all required details in it to properly analyze this issue. Current details you provided don't help much to proceed further.

Issue Template

## Bug report

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2. '...'
4. See error or incorrect behavior

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---

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