Xamarin.Android FCM和解析异常

Question

我能够实现Firebase通知并将通知从Firebase控制台成功发送到客户端。当我使用Parse SDK通过Parse Dashboard发送通知时，就会出现问题。我正在使用Xamarin.Android，而本机与带有FCM和Parse的本机Android并不完全相同。通过分析仪表板发送通知时，我注意到客户端上出现以下异常：

Java.Lang.RuntimeException: Unable to instantiate service com.parse.fcm.ParseFirebaseMessagingService: java.lang.ClassNotFoundException: Didn't find class 

当分析文档告诉我要在下面实现以下清单时：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.xamarin.fcmexample" android:installLocation="preferExternal">
    <uses-sdk android:minSdkVersion="20" android:targetSdkVersion="25" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
    <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="g" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme">
        <receiver android:name="com.google.firebase.iid.FirebaseInstanceIdInternalReceiver" android:exported="false" />
        <receiver android:name="com.google.firebase.iid.FirebaseInstanceIdReceiver" android:exported="true" android:permission="com.google.android.c2dm.permission.SEND">
            <intent-filter>
                <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
                <category android:name="${applicationId}" />
            </intent-filter>
        </receiver>
        <service android:name="com.parse.fcm.ParseFirebaseInstanceIdService" android:exported="true">
            <intent-filter>
                <action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
            </intent-filter>
        </service>
        <service android:name="com.parse.fcm.ParseFirebaseMessagingService">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT" />
            </intent-filter>
        </service>
        <receiver android:name="com.parse.ParsePushBroadcastReceiver" android:exported="false">
            <intent-filter>
                <action android:name="com.parse.push.intent.RECEIVE" />
                <action android:name="com.parse.push.intent.DELETE" />
                <action android:name="com.parse.push.intent.OPEN" />
            </intent-filter>
        </receiver>
    </application>
</manifest>

想知道是否缺少任何使Xamarin.Android + Parse SDK + FCM正常运行的东西。谢谢。