Class not found exception

[BrianMwas]

Hello people. I can not seem to send notifications to my flutter app. It keeps sending a classNotFound exception for the service, .java.MyFirebaseAppService which it says can not be found. Whenever I try to send a message from the firebase console it crashes unexpectedly.
Here is the error log for the crash.

java.lang.RuntimeException: Unable to instantiate service com.myapp.MyApp.MyFirebaseMessagingService: java.lang.ClassNotFoundException: Didn't find class "com.myapp.MyApp.MyFirebaseMessagingService" on path: DexPathList[[zip file "/data/app/com.myapp.MyApp-2_H2R81paYjm5b8ZDse8Uw==/base.apk"],nativeLibraryDirectories=[/data/app/com.myapp.MyApp-2_H2R81paYjm5b8ZDse8Uw==/lib/arm64, /data/app/com.myapp.MyApp-2_H2R81paYjm5b8ZDse8Uw==/base.apk!/lib/arm64-v8a, /system/lib64, /vendor/lib64]]
E/AndroidRuntime( 5956):    at android.app.ActivityThread.handleCreateService(ActivityThread.java:3577)
E/AndroidRuntime( 5956):    at android.app.ActivityThread.-wrap4(Unknown Source:0)
E/AndroidRuntime( 5956):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1862)
E/AndroidRuntime( 5956):    at android.os.Handler.dispatchMessage(Handler.java:106)
E/AndroidRuntime( 5956):    at android.os.Looper.loop(Looper.java:198)
E/AndroidRuntime( 5956):    at android.app.ActivityThread.main(ActivityThread.java:7055)
E/AndroidRuntime( 5956):    at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime( 5956):    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:523)
E/AndroidRuntime( 5956):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:836)
E/AndroidRuntime( 5956): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.myapp.MyAppMyFirebaseMessagingService" on path: DexPathList[[zip file "/data/app/com.myapp.MyApp-2_H2R81paYjm5b8ZDse8Uw==/base.apk"],nativeLibraryDirectories=[/data/app/com.myapp.MyApp-2_H2R81paYjm5b8ZDse8Uw==/lib/arm64, /data/app/com.myapp.MyApp-2_H2R81paYjm5b8ZDse8Uw==/base.apk!/lib/arm64-v8a, /system/lib64, /vendor/lib64]]
E/AndroidRuntime( 5956):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
E/AndroidRuntime( 5956):    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
E/AndroidRuntime( 5956):    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
E/AndroidRuntime( 5956):    at android.app.ActivityThread.handleCreateService(ActivityThread.java:3574)
E/AndroidRuntime( 5956):    ... 8 more

I first thought it was the android manifests problem but I the manifest looks okay and the service has been recorded, just can not be able to find where I am doing it wrong.

<activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:showWhenLocked="true"
            android:turnScreenOn="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />
            <!-- Displays an Android View that continues showing the launch screen
                 Drawable until Flutter paints its first frame, then this splash
                 screen fades out. A splash screen is useful to avoid any visual
                 gap between the end of Android's launch screen and the painting of
                 Flutter's first frame. -->
            <meta-data
              android:name="io.flutter.embedding.android.SplashScreenDrawable"
              android:resource="@drawable/launch_background"
              />

            <meta-data
                    android:name="com.google.firebase.messaging.default_notification_icon"
                    android:resource="@mipmap/ic_logo" />

            <meta-data
                    android:name="com.google.firebase.messaging.default_notification_color"
                    android:resource="@color/colorAccent" />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
            <intent-filter>
                <action android:name="FLUTTER_NOTIFICATION_CLICK" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

        <service
                android:name=".service.MyFirebaseMessagingService"
                >
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT" />
            </intent-filter>
        </service>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>

Any help will be highly appreciated.

[BrianMwas]

Closing this as it is a duplicate of #3990