Xamarin Media Plugin doesn't works on Android

Hi,
I've installed the plugin "Xam.Plugin.Media".
The plugin works fine on IOS but on Andorid the app crash as soon it starts.

I have followed the readme.txt that come after the installation of the plugin, so my files are:

MainActivity.cs:

using System;

using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Plugin.Permissions;
using Plugin.Permissions.Abstractions;
using FFImageLoading.Forms.Droid;

namespace SgatMobileV2.Droid {
    [Activity(Label = "SgatMobileV2", Icon = "@drawable/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity {
        protected override void OnCreate(Bundle bundle) {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(bundle);

            global::Xamarin.Forms.Forms.Init(this, bundle);

            CachedImageRenderer.Init(enableFastRenderer: true); // Inizializza il plugin FFImageLoading

            LoadApplication(new App());
        }

        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, global::Android.Content.PM.Permission[] grantResults) {
            PermissionsImplementation.Current.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }
}

Resources/xml/file_paths.xml:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
  <external-files-path name="my_images" path="Pictures" />
  <external-files-path name="my_movies" path="Movies" />
</paths>

AndroidManifest.xml:

<?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="it.volos.SgatMobile" android:installLocation="auto">
  <uses-sdk android:minSdkVersion="23" android:targetSdkVersion="26" />
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
  <uses-permission android:name="android.permission.CAMERA" />
  <application android:label="SgatMobileV2.Android" android:icon="@drawable/icon">
    <provider android:name="android.support.v4.content.FileProvider" android:authorities="it.volos.SgatMobile.fileprovider" android:exported="false" android:grantUriPermissions="true">
      <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths"></meta-data>
    </provider>
  </application>
</manifest>

But after the app starts, this error is triggered:

System.NullReferenceException: Object reference not set to an instance of an object.

Can anyone help me please?

Thank you!