diff --git a/app/dependencies.gradle b/app/dependencies.gradle
index 52a288ead..24c889675 100644
--- a/app/dependencies.gradle
+++ b/app/dependencies.gradle
@@ -15,23 +15,27 @@ dependencies {
     implementation 'com.coolerfall:android-http-download-manager:1.6.1'
 
     // images
-    def glideVersion = '4.6.1'
+    def glideVersion = '4.7.1'
     implementation "com.github.bumptech.glide:glide:${glideVersion}"
     implementation "com.github.bumptech.glide:okhttp3-integration:${glideVersion}"
     kapt           "com.github.bumptech.glide:compiler:${glideVersion}"
 
     // architecture
-    implementation 'com.evernote:android-job:1.2.5'
+    implementation 'com.evernote:android-job:1.2.6'
     implementation 'org.greenrobot:eventbus:3.1.1'
 
     // json
-    implementation 'com.google.code.gson:gson:2.8.4'
+    implementation 'com.google.code.gson:gson:2.8.5'
+    implementation 'com.squareup.moshi:moshi:1.6.0'
 
     // json:api
     def retrofitVersion = '2.4.0'
     implementation "com.squareup.retrofit2:retrofit:${retrofitVersion}"
     implementation "com.squareup.retrofit2:converter-moshi:${retrofitVersion}"
-    implementation 'moe.banana:moshi-jsonapi:3.3.1'
+
+    def moshijsonapiVersion = '3.5.0'
+    implementation "moe.banana:moshi-jsonapi:${moshijsonapiVersion}"
+    implementation "moe.banana:moshi-jsonapi-retrofit-converter:${moshijsonapiVersion}"
 
     // user interface
     implementation 'com.github.barteksc:android-pdf-viewer:2.8.1'
@@ -39,7 +43,7 @@ dependencies {
     implementation 'com.github.Commit451:bypasses:1.1.0'
 
     // video
-    implementation 'com.devbrackets.android:exomedia:4.1.0'
+    implementation 'com.devbrackets.android:exomedia:4.2.1'
 
     // view binding
     def butterknifeVersion = '8.8.1'
@@ -56,11 +60,11 @@ dependencies {
     implementation "com.google.android.gms:play-services-gcm:15.0.1"
 
     // firebase
-    implementation "com.crashlytics.sdk.android:crashlytics:2.9.2"
-    implementation "com.google.firebase:firebase-core:15.0.2"
+    implementation "com.crashlytics.sdk.android:crashlytics:2.9.3"
+    implementation "com.google.firebase:firebase-core:16.0.0"
 
     // support libraries
-    def supportVersion = '27.0.2'
+    def supportVersion = '27.1.1'
     implementation "com.android.support:support-v4:${supportVersion}"
     implementation "com.android.support:appcompat-v7:${supportVersion}"
     implementation "com.android.support:cardview-v7:${supportVersion}"
diff --git a/app/src/main/java/de/xikolo/controllers/base/BasePresenterActivity.java b/app/src/main/java/de/xikolo/controllers/base/BasePresenterActivity.java
index b72b2775f..39aabf16d 100644
--- a/app/src/main/java/de/xikolo/controllers/base/BasePresenterActivity.java
+++ b/app/src/main/java/de/xikolo/controllers/base/BasePresenterActivity.java
@@ -38,6 +38,7 @@ protected void onCreate(Bundle savedInstanceState) {
     private void initLoader() {
         // LoaderCallbacks as an object, so no hint regarding Loader will be leak to the subclasses.
         getSupportLoaderManager().initLoader(loaderId(), null, new LoaderManager.LoaderCallbacks<P>() {
+            @NonNull
             @Override
             public final Loader<P> onCreateLoader(int id, Bundle args) {
                 if (PRESENTER_LIFECYCLE_LOGGING) Log.i(TAG, "onCreateLoader");
@@ -45,14 +46,15 @@ public final Loader<P> onCreateLoader(int id, Bundle args) {
             }
 
             @Override
-            public final void onLoadFinished(Loader<P> loader, P presenter) {
+            public final void onLoadFinished(@NonNull Loader<P> loader, P presenter) {
                 if (PRESENTER_LIFECYCLE_LOGGING) Log.i(TAG, "onLoadFinished");
                 BasePresenterActivity.this.presenter = presenter;
+                presenter.onViewAttached(getPresenterView());
                 onPresenterCreatedOrRestored(presenter);
             }
 
             @Override
-            public final void onLoaderReset(Loader<P> loader) {
+            public final void onLoaderReset(@NonNull Loader<P> loader) {
                 if (PRESENTER_LIFECYCLE_LOGGING) Log.i(TAG, "onLoaderReset");
                 BasePresenterActivity.this.presenter = null;
                 onPresenterDestroyed();
@@ -63,12 +65,12 @@ public final void onLoaderReset(Loader<P> loader) {
     @Override
     protected void onStart() {
         super.onStart();
-        presenter.onViewAttached(getPresenterView());
+        if (presenter != null) presenter.onViewAttached(getPresenterView());
     }
 
     @Override
     protected void onStop() {
-        presenter.onViewDetached();
+        if (presenter != null) presenter.onViewDetached();
         super.onStop();
     }
 
@@ -77,7 +79,7 @@ protected void onStop() {
      */
     @NonNull
     protected String tag() {
-        return TAG;
+        return this.getClass().getSimpleName();
     }
 
     /**
@@ -88,7 +90,7 @@ protected String tag() {
     protected abstract PresenterFactory<P> getPresenterFactory();
 
     /**
-     * Hook for subclasses that deliver the {@link Presenter} before its View is attached.
+     * Hook for subclasses that deliver the {@link Presenter} when created or restored.
      * Can be use to initialize the Presenter or simple hold a reference to it.
      */
     protected void onPresenterCreatedOrRestored(@NonNull P presenter) {
diff --git a/app/src/main/java/de/xikolo/controllers/base/BasePresenterFragment.java b/app/src/main/java/de/xikolo/controllers/base/BasePresenterFragment.java
index fa772bc98..790f74faf 100644
--- a/app/src/main/java/de/xikolo/controllers/base/BasePresenterFragment.java
+++ b/app/src/main/java/de/xikolo/controllers/base/BasePresenterFragment.java
@@ -38,6 +38,7 @@ public void onActivityCreated(Bundle savedInstanceState) {
     private void initLoader() {
         // LoaderCallbacks as an object, so no hint regarding loader will be leak to the subclasses.
         getLoaderManager().initLoader(loaderId(), null, new LoaderManager.LoaderCallbacks<P>() {
+            @NonNull
             @Override
             public final Loader<P> onCreateLoader(int id, Bundle args) {
                 if (PRESENTER_LIFECYCLE_LOGGING) Log.i(TAG, "onCreateLoader-" + tag());
@@ -45,14 +46,15 @@ public final Loader<P> onCreateLoader(int id, Bundle args) {
             }
 
             @Override
-            public final void onLoadFinished(Loader<P> loader, P presenter) {
+            public final void onLoadFinished(@NonNull Loader<P> loader, P presenter) {
                 if (PRESENTER_LIFECYCLE_LOGGING) Log.i(TAG, "onLoadFinished-" + tag());
                 BasePresenterFragment.this.presenter = presenter;
+                presenter.onViewAttached(getPresenterView());
                 onPresenterCreatedOrRestored(presenter);
             }
 
             @Override
-            public final void onLoaderReset(Loader<P> loader) {
+            public final void onLoaderReset(@NonNull Loader<P> loader) {
                 if (PRESENTER_LIFECYCLE_LOGGING) Log.i(TAG, "onLoaderReset-" + tag());
                 BasePresenterFragment.this.presenter = null;
                 onPresenterDestroyed();
@@ -63,12 +65,12 @@ public final void onLoaderReset(Loader<P> loader) {
     @Override
     public void onStart() {
         super.onStart();
-        presenter.onViewAttached(getPresenterView());
+        if (presenter != null) presenter.onViewAttached(getPresenterView());
     }
 
     @Override
     public void onStop() {
-        presenter.onViewDetached();
+        if (presenter != null) presenter.onViewDetached();
         super.onStop();
     }
 
@@ -82,7 +84,7 @@ public void setTitle(CharSequence title) {
      */
     @NonNull
     protected String tag() {
-        return TAG;
+        return this.getClass().getSimpleName();
     }
 
     /**
@@ -93,7 +95,7 @@ protected String tag() {
     protected abstract PresenterFactory<P> getPresenterFactory();
 
     /**
-     * Hook for subclasses that deliver the {@link Presenter} before its View is attached.
+     * Hook for subclasses that deliver the {@link Presenter} when created or restored.
      * Can be use to initialize the Presenter or simple hold a reference to it.
      */
     protected void onPresenterCreatedOrRestored(@NonNull P presenter) {
diff --git a/app/src/main/java/de/xikolo/models/base/Sync.java b/app/src/main/java/de/xikolo/models/base/Sync.java
index a8397b51f..07300ec28 100644
--- a/app/src/main/java/de/xikolo/models/base/Sync.java
+++ b/app/src/main/java/de/xikolo/models/base/Sync.java
@@ -81,10 +81,8 @@ public static <S extends RealmModel, T extends Resource & RealmAdapter<S>> Data<
         public String[] run() {
             final List<String> ids = new ArrayList<>();
 
-            Realm realm = Realm.getDefaultInstance();
-            realm.executeTransaction(new Realm.Transaction() {
-                @Override
-                public void execute(Realm realm) {
+            try (Realm realmInstance = Realm.getDefaultInstance()) {
+                realmInstance.executeTransaction(realm -> {
                     for (T item : items) {
                         if (beforeCommitCallback != null) {
                             beforeCommitCallback.beforeCommit(realm, item.convertToRealmObject());
@@ -116,9 +114,8 @@ public void execute(Realm realm) {
 
                         results.deleteAllFromRealm();
                     } else if (Config.DEBUG) Log.d(TAG, "DATA: Deleted 0 local resources from type " + clazz.getSimpleName());
-                }
-            });
-            realm.close();
+                });
+            }
 
             return ids.toArray(new String[0]);
         }
@@ -127,14 +124,14 @@ public void execute(Realm realm) {
 
     public static class Included<S extends RealmModel, T extends Resource & RealmAdapter<S>> extends Sync<S, T> {
 
-        private Document<?> document;
+        private Document document;
 
-        private Included(Class<S> clazz, Document<?> document) {
+        private Included(Class<S> clazz, Document document) {
             super(clazz);
             this.document = document;
         }
 
-        public static <S extends RealmModel> Included<S, ?> with(Class<S> clazz, final Document<?> document) {
+        public static <S extends RealmModel> Included<S, ?> with(Class<S> clazz, final Document document) {
             return new Included<>(clazz, document);
         }
 
@@ -151,10 +148,8 @@ public String[] run() {
 
             final List<String> ids = new ArrayList<>();
 
-            Realm realm = Realm.getDefaultInstance();
-            realm.executeTransaction(new Realm.Transaction() {
-                @Override
-                public void execute(Realm realm) {
+            try (Realm realmInstance = Realm.getDefaultInstance()) {
+                realmInstance.executeTransaction(realm -> {
                     for (Resource resource : document.getIncluded()) {
                         if (resource instanceof RealmAdapter) {
                             RealmAdapter adapter = (RealmAdapter) resource;
@@ -192,9 +187,8 @@ public void execute(Realm realm) {
 
                         results.deleteAllFromRealm();
                     } else if (Config.DEBUG) Log.d(TAG, "INCLUDED: Deleted 0 local resources from type " + clazz.getSimpleName());
-                }
-            });
-            realm.close();
+                });
+            }
 
             return ids.toArray(new String[0]);
         }
diff --git a/app/src/main/java/de/xikolo/network/ApiService.java b/app/src/main/java/de/xikolo/network/ApiService.java
index 15ee84f0a..fc96dc373 100644
--- a/app/src/main/java/de/xikolo/network/ApiService.java
+++ b/app/src/main/java/de/xikolo/network/ApiService.java
@@ -26,6 +26,7 @@
 import de.xikolo.models.SubtitleCue;
 import de.xikolo.models.SubtitleTrack;
 import de.xikolo.models.Video;
+import moe.banana.jsonapi2.JsonApiConverterFactory;
 import moe.banana.jsonapi2.ResourceAdapterFactory;
 import okhttp3.Interceptor;
 import okhttp3.OkHttpClient;
diff --git a/app/src/main/java/de/xikolo/network/JsonApiConverterFactory.java b/app/src/main/java/de/xikolo/network/JsonApiConverterFactory.java
deleted file mode 100644
index 3a83c7207..000000000
--- a/app/src/main/java/de/xikolo/network/JsonApiConverterFactory.java
+++ /dev/null
@@ -1,195 +0,0 @@
-package de.xikolo.network;
-
-import com.squareup.moshi.JsonAdapter;
-import com.squareup.moshi.Moshi;
-import com.squareup.moshi.Types;
-
-import java.io.IOException;
-import java.lang.annotation.Annotation;
-import java.lang.reflect.Array;
-import java.lang.reflect.ParameterizedType;
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.List;
-
-import moe.banana.jsonapi2.ArrayDocument;
-import moe.banana.jsonapi2.Document;
-import moe.banana.jsonapi2.ObjectDocument;
-import moe.banana.jsonapi2.Resource;
-import moe.banana.jsonapi2.ResourceIdentifier;
-import okhttp3.MediaType;
-import okhttp3.RequestBody;
-import okhttp3.ResponseBody;
-import okio.Buffer;
-import retrofit2.Converter;
-import retrofit2.Retrofit;
-
-/**
- * See https://gist.github.com/kamikat/baa7d086f932b0dc4fc3f9f02e37a485
- */
-
-@SuppressWarnings("unchecked")
-public final class JsonApiConverterFactory extends Converter.Factory {
-
-    public static JsonApiConverterFactory create() {
-        return create(new Moshi.Builder().build());
-    }
-
-    public static JsonApiConverterFactory create(Moshi moshi) {
-        return new JsonApiConverterFactory(moshi, false);
-    }
-
-    private final Moshi moshi;
-    private final boolean lenient;
-
-    private JsonApiConverterFactory(Moshi moshi, boolean lenient) {
-        if (moshi == null) throw new NullPointerException("moshi == null");
-        this.moshi = moshi;
-        this.lenient = lenient;
-    }
-
-    public JsonApiConverterFactory asLenient() {
-        return new JsonApiConverterFactory(moshi, true);
-    }
-
-    private JsonAdapter<?> getAdapterFromType(Type type) {
-        Class<?> rawType = Types.getRawType(type);
-        JsonAdapter<?> adapter;
-        if (rawType.isArray() && ResourceIdentifier.class.isAssignableFrom(rawType.getComponentType())) {
-            adapter = moshi.adapter(Types.newParameterizedType(Document.class, rawType.getComponentType()));
-        } else if (List.class.isAssignableFrom(rawType) && type instanceof ParameterizedType) {
-            Type typeParameter = ((ParameterizedType) type).getActualTypeArguments()[0];
-            if (typeParameter instanceof Class<?> && ResourceIdentifier.class.isAssignableFrom((Class<?>) typeParameter)) {
-                adapter = moshi.adapter(Types.newParameterizedType(Document.class, typeParameter));
-            } else {
-                return null;
-            }
-        } else if (ResourceIdentifier.class.isAssignableFrom(rawType)) {
-            adapter = moshi.adapter(Types.newParameterizedType(Document.class, rawType));
-        } else if (Document.class.isAssignableFrom(rawType)) {
-            adapter = moshi.adapter(Types.newParameterizedType(Document.class, Resource.class));
-        } else {
-            return null;
-        }
-        return adapter;
-    }
-
-    @Override
-    public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {
-        JsonAdapter<?> adapter = getAdapterFromType(type);
-        if (adapter == null) {
-            return null;
-        }
-        if (lenient) {
-            adapter = adapter.lenient();
-        }
-        return new MoshiResponseBodyConverter<>((JsonAdapter<Document<?>>) adapter, type);
-    }
-
-    @Override
-    public Converter<?, RequestBody> requestBodyConverter(Type type, Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) {
-        JsonAdapter<?> adapter = getAdapterFromType(type);
-        if (adapter == null) {
-            return null;
-        }
-        if (lenient) {
-            adapter = adapter.lenient();
-        }
-        return new MoshiRequestBodyConverter<>((JsonAdapter<Document<?>>) adapter, type);
-    }
-
-    private static final MediaType MEDIA_TYPE = MediaType.parse("application/json; charset=UTF-8");
-
-    private static class MoshiResponseBodyConverter<R> implements Converter<ResponseBody, R> {
-        private final JsonAdapter<Document<?>> adapter;
-        private final Class<R> rawType;
-
-        MoshiResponseBodyConverter(JsonAdapter<Document<?>> adapter, Type type) {
-            this.adapter = adapter;
-            this.rawType = (Class<R>) Types.getRawType(type);
-        }
-
-        @Override
-        public R convert(ResponseBody value) throws IOException {
-            try {
-                Document<?> document = adapter.fromJson(value.source());
-                if (Document.class.isAssignableFrom(rawType)) {
-                    return (R) document;
-                } else if (List.class.isAssignableFrom(rawType)) {
-                    ArrayDocument arrayDocument = document.asArrayDocument();
-                    List a;
-                    if (rawType.isAssignableFrom(ArrayList.class)) {
-                        a = new ArrayList();
-                    } else {
-                        a = (List) rawType.newInstance();
-                    }
-                    a.addAll(arrayDocument);
-                    return (R) a;
-                } else if (rawType.isArray()) {
-                    ArrayDocument<?> arrayDocument = document.asArrayDocument();
-                    Object a = Array.newInstance(rawType.getComponentType(), arrayDocument.size());
-                    for (int i = 0; i != Array.getLength(a); i++) {
-                        Array.set(a, i, arrayDocument.get(i));
-                    }
-                    return (R) a;
-                } else {
-                    return (R) document.asObjectDocument().get();
-                }
-            } catch (InstantiationException e) {
-                throw new RuntimeException("Cannot find default constructor of [" + rawType.getCanonicalName() + "].", e);
-            } catch (IllegalAccessException e) {
-                throw new RuntimeException("Cannot access default constructor of [" + rawType.getCanonicalName() + "].", e);
-            } finally {
-                value.close();
-            }
-        }
-    }
-
-    private static class MoshiRequestBodyConverter<T> implements Converter<T, RequestBody> {
-
-        private final JsonAdapter<Document<?>> adapter;
-        private final Class<T> rawType;
-
-        MoshiRequestBodyConverter(JsonAdapter<Document<?>> adapter, Type type) {
-            this.adapter = adapter;
-            this.rawType = (Class<T>) Types.getRawType(type);
-        }
-
-        @Override
-        public RequestBody convert(T value) throws IOException {
-            Document document;
-            if (Document.class.isAssignableFrom(rawType)) {
-                document = (Document) value;
-            } else if (List.class.isAssignableFrom(rawType)) {
-                ArrayDocument arrayDocument = new ArrayDocument();
-                List a = ((List) value);
-                if (!a.isEmpty() && a.get(0) != null && ((ResourceIdentifier) a.get(0)).getDocument() != null) {
-                    arrayDocument = ((ResourceIdentifier) a.get(0)).getDocument().asArrayDocument();
-                }
-                arrayDocument.addAll(a);
-                document = arrayDocument;
-            } else if (rawType.isArray()) {
-                ArrayDocument arrayDocument = new ArrayDocument();
-                if (Array.getLength(value) > 0 && ((ResourceIdentifier) Array.get(value, 0)).getDocument() != null) {
-                    arrayDocument = ((ResourceIdentifier) Array.get(value, 0)).getDocument().asArrayDocument();
-                }
-                for (int i = 0; i != Array.getLength(value); i++) {
-                    arrayDocument.add((ResourceIdentifier) Array.get(value, i));
-                }
-                document = arrayDocument;
-            } else {
-                ResourceIdentifier data = ((ResourceIdentifier) value);
-                ObjectDocument objectDocument = new ObjectDocument();
-                if (data.getDocument() != null) {
-                    objectDocument = data.getDocument().asObjectDocument();
-                }
-                objectDocument.set(data);
-                document = objectDocument;
-            }
-            Buffer buffer = new Buffer();
-            adapter.toJson(buffer, document);
-            return RequestBody.create(MEDIA_TYPE, buffer.readByteString());
-        }
-    }
-
-}
diff --git a/app/src/main/java/de/xikolo/presenters/channels/ChannelDetailsPresenter.java b/app/src/main/java/de/xikolo/presenters/channels/ChannelDetailsPresenter.java
index 5638cc790..6065ad906 100644
--- a/app/src/main/java/de/xikolo/presenters/channels/ChannelDetailsPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/channels/ChannelDetailsPresenter.java
@@ -55,8 +55,10 @@ public void onViewAttached(ChannelDetailsView v) {
 
             coursesPromise = getCoursesPromise();
 
-            getViewOrThrow().showContent();
-            getViewOrThrow().setupView(channel);
+            if (isViewAttached()) {
+                getView().showContent();
+                getView().setupView(channel);
+            }
         });
     }
 
@@ -91,7 +93,7 @@ private RealmResults getCoursesPromise() {
                 courseList.clear();
                 courseList.add(channel.description, new ArrayList<>());
                 buildCourseList();
-                getViewOrThrow().showCourseList(courseList);
+                getView().showCourseList(courseList);
             }
         });
     }
diff --git a/app/src/main/java/de/xikolo/presenters/course/CourseDetailsPresenter.java b/app/src/main/java/de/xikolo/presenters/course/CourseDetailsPresenter.java
index a43a7b047..321209d97 100644
--- a/app/src/main/java/de/xikolo/presenters/course/CourseDetailsPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/course/CourseDetailsPresenter.java
@@ -5,7 +5,6 @@
 import de.xikolo.models.Course;
 import de.xikolo.presenters.base.LoadingStatePresenter;
 import io.realm.Realm;
-import io.realm.RealmChangeListener;
 
 import static de.xikolo.jobs.base.RequestJobCallback.ErrorCode.NO_NETWORK;
 
@@ -42,12 +41,11 @@ public void onViewAttached(CourseDetailsView v) {
             requestCourse(false);
         }
 
-        coursePromise = courseManager.getCourse(courseId, realm, new RealmChangeListener<Course>() {
-            @Override
-            public void onChange(Course c) {
-                course = c;
-                getViewOrThrow().showContent();
-                getViewOrThrow().setupView(course);
+        coursePromise = courseManager.getCourse(courseId, realm, (c) -> {
+            course = c;
+            if (isViewAttached()) {
+                getView().showContent();
+                getView().setupView(course);
             }
         });
     }
diff --git a/app/src/main/java/de/xikolo/presenters/course/LearningsPresenter.java b/app/src/main/java/de/xikolo/presenters/course/LearningsPresenter.java
index d765a4a6c..91eb926fe 100644
--- a/app/src/main/java/de/xikolo/presenters/course/LearningsPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/course/LearningsPresenter.java
@@ -9,7 +9,6 @@
 import de.xikolo.models.Section;
 import de.xikolo.presenters.base.LoadingStatePresenter;
 import io.realm.Realm;
-import io.realm.RealmChangeListener;
 import io.realm.RealmResults;
 
 public class LearningsPresenter extends LoadingStatePresenter<LearningsView> {
@@ -45,20 +44,16 @@ public void onViewAttached(LearningsView v) {
             requestSectionListWithItems(false);
         }
 
-        coursePromise = courseManager.getCourse(courseId, realm, new RealmChangeListener<Course>() {
-            @Override
-            public void onChange(Course course) {
-                getViewOrThrow().setTitle(course.title);
-            }
+        coursePromise = courseManager.getCourse(courseId, realm, (course) -> {
+            if (isViewAttached()) getView().setTitle(course.title);
         });
 
-        itemsPromise = itemManager.listAccessibleItemsForCourse(courseId, realm, new RealmChangeListener<RealmResults<Item>>() {
-            @Override
-            public void onChange(RealmResults<Item> items) {
-                if (items.size() > 0) {
-                    itemList = items;
-                    getViewOrThrow().showContent();
-                    getViewOrThrow().setupSections(Section.listForCourse(courseId));
+        itemsPromise = itemManager.listAccessibleItemsForCourse(courseId, realm, (items) -> {
+            if (items.size() > 0) {
+                itemList = items;
+                if (isViewAttached()) {
+                    getView().showContent();
+                    getView().setupSections(Section.listForCourse(courseId));
                 }
             }
         });
diff --git a/app/src/main/java/de/xikolo/presenters/course_items/RichTextPresenter.java b/app/src/main/java/de/xikolo/presenters/course_items/RichTextPresenter.java
index 4b0fae5ae..735bb963c 100644
--- a/app/src/main/java/de/xikolo/presenters/course_items/RichTextPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/course_items/RichTextPresenter.java
@@ -3,7 +3,6 @@
 import de.xikolo.config.Config;
 import de.xikolo.models.RichText;
 import de.xikolo.utils.LanalyticsUtil;
-import io.realm.RealmChangeListener;
 import io.realm.RealmResults;
 
 public class RichTextPresenter extends ItemPresenter<RichTextView> {
@@ -25,13 +24,12 @@ public void onViewAttached(RichTextView v) {
             requestItem(false);
         }
 
-        richTextPromise = itemManager.getRichTextForItem(item.contentId, realm, new RealmChangeListener<RealmResults<RichText>>() {
-            @Override
-            public void onChange(RealmResults<RichText> result) {
-                if (result.size() > 0) {
-                    richText = realm.copyFromRealm(result.first());
-                    getViewOrThrow().showContent();
-                    getViewOrThrow().setupView(item, richText);
+        richTextPromise = itemManager.getRichTextForItem(item.contentId, realm, (result) -> {
+            if (result.size() > 0) {
+                richText = realm.copyFromRealm(result.first());
+                if (isViewAttached()) {
+                    getView().showContent();
+                    getView().setupView(item, richText);
                 }
             }
         });
diff --git a/app/src/main/java/de/xikolo/presenters/course_items/VideoPreviewPresenter.java b/app/src/main/java/de/xikolo/presenters/course_items/VideoPreviewPresenter.java
index 92fc93f75..0f0a0860c 100644
--- a/app/src/main/java/de/xikolo/presenters/course_items/VideoPreviewPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/course_items/VideoPreviewPresenter.java
@@ -5,7 +5,6 @@
 import de.xikolo.models.Video;
 import de.xikolo.utils.CastUtil;
 import de.xikolo.utils.LanalyticsUtil;
-import io.realm.RealmChangeListener;
 import io.realm.RealmResults;
 
 public class VideoPreviewPresenter extends ItemPresenter<VideoPreviewView> {
@@ -27,13 +26,12 @@ public void onViewAttached(VideoPreviewView v) {
             requestItem(false);
         }
 
-        videoPromise = itemManager.getVideoForItem(item.contentId, realm, new RealmChangeListener<RealmResults<Video>>() {
-            @Override
-            public void onChange(RealmResults<Video> result) {
-                if (result.size() > 0) {
-                    video = realm.copyFromRealm(result.first());
-                    getViewOrThrow().showContent();
-                    getViewOrThrow().setupView(course, section, item, video);
+        videoPromise = itemManager.getVideoForItem(item.contentId, realm, (result) -> {
+            if (result.size() > 0) {
+                video = realm.copyFromRealm(result.first());
+                if (isViewAttached()) {
+                    getView().showContent();
+                    getView().setupView(course, section, item, video);
                 }
             }
         });
diff --git a/app/src/main/java/de/xikolo/presenters/main/ChannelListPresenter.java b/app/src/main/java/de/xikolo/presenters/main/ChannelListPresenter.java
index 58a940e92..9d02bc73a 100644
--- a/app/src/main/java/de/xikolo/presenters/main/ChannelListPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/main/ChannelListPresenter.java
@@ -41,8 +41,11 @@ private RealmChangeListener<RealmResults<Channel>> getChannelListRealmChangeList
         return results -> {
             if (results.size() > 0) {
                 channelList = results;
-                getViewOrThrow().showContent();
-                getViewOrThrow().showChannelList(channelList);
+
+                if (isViewAttached()) {
+                    getView().showContent();
+                    getView().showChannelList(channelList);
+                }
             }
         };
     }
diff --git a/app/src/main/java/de/xikolo/presenters/main/CourseListPresenter.java b/app/src/main/java/de/xikolo/presenters/main/CourseListPresenter.java
index 36faf81c8..965f11891 100644
--- a/app/src/main/java/de/xikolo/presenters/main/CourseListPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/main/CourseListPresenter.java
@@ -54,7 +54,7 @@ public void onSearch(final String query, boolean withEnrollment) {
             this.courseListPromise = courseManager.searchCourses(query, withEnrollment, realm, results -> {
                 courseList.clear();
                 courseList.add(null, results);
-                getViewOrThrow().showCourseList(courseList);
+                if (isViewAttached()) getView().showCourseList(courseList);
             });
         } else {
             setCourseListPromise();
@@ -65,8 +65,10 @@ public void onSearch(final String query, boolean withEnrollment) {
 
     protected RealmChangeListener<RealmResults<Course>> getCourseListChangeListener() {
         return results -> {
-            getViewOrThrow().showContent();
-            updateContent();
+            if (isViewAttached()) {
+                getView().showContent();
+                updateContent();
+            }
         };
     }
 
diff --git a/app/src/main/java/de/xikolo/presenters/main/NavigationPresenter.java b/app/src/main/java/de/xikolo/presenters/main/NavigationPresenter.java
index 01d209e46..01a11620d 100644
--- a/app/src/main/java/de/xikolo/presenters/main/NavigationPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/main/NavigationPresenter.java
@@ -1,10 +1,8 @@
 package de.xikolo.presenters.main;
 
 import de.xikolo.managers.AnnouncementManager;
-import de.xikolo.models.Announcement;
 import de.xikolo.presenters.base.Presenter;
 import io.realm.Realm;
-import io.realm.RealmChangeListener;
 import io.realm.RealmResults;
 
 public class NavigationPresenter extends Presenter<NavigationView> {
@@ -24,11 +22,8 @@ public class NavigationPresenter extends Presenter<NavigationView> {
     public void onViewAttached(NavigationView view) {
         super.onViewAttached(view);
 
-        this.announcementListPromise = announcementManager.listGlobalAnnouncements(realm, new RealmChangeListener<RealmResults<Announcement>>() {
-            @Override
-            public void onChange(RealmResults<Announcement> results) {
-                getViewOrThrow().updateDrawer();
-            }
+        this.announcementListPromise = announcementManager.listGlobalAnnouncements(realm, (announcements) -> {
+            if (isViewAttached()) getView().updateDrawer();
         });
     }
 
diff --git a/app/src/main/java/de/xikolo/presenters/main/NewsListPresenter.java b/app/src/main/java/de/xikolo/presenters/main/NewsListPresenter.java
index 4db98cbc1..128025828 100644
--- a/app/src/main/java/de/xikolo/presenters/main/NewsListPresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/main/NewsListPresenter.java
@@ -46,13 +46,13 @@ public void onViewAttached(NewsListView view) {
     }
 
     private RealmChangeListener<RealmResults<Announcement>> getAnnouncementListRealmChangeLictener() {
-        return new RealmChangeListener<RealmResults<Announcement>>() {
-            @Override
-            public void onChange(RealmResults<Announcement> results) {
-                if (results.size() > 0) {
-                    announcementList = results;
-                    getViewOrThrow().showContent();
-                    getViewOrThrow().showAnnouncementList(announcementList);
+        return (results) -> {
+            if (results.size() > 0) {
+                announcementList = results;
+
+                if (isViewAttached()) {
+                    getView().showContent();
+                    getView().showAnnouncementList(announcementList);
                 }
             }
         };
diff --git a/app/src/main/java/de/xikolo/presenters/main/ProfilePresenter.java b/app/src/main/java/de/xikolo/presenters/main/ProfilePresenter.java
index 24a4e2144..0b89038ae 100644
--- a/app/src/main/java/de/xikolo/presenters/main/ProfilePresenter.java
+++ b/app/src/main/java/de/xikolo/presenters/main/ProfilePresenter.java
@@ -3,12 +3,10 @@
 import de.xikolo.jobs.base.RequestJobCallback;
 import de.xikolo.managers.CourseManager;
 import de.xikolo.managers.UserManager;
-import de.xikolo.models.Enrollment;
 import de.xikolo.models.Profile;
 import de.xikolo.models.User;
 import de.xikolo.presenters.base.LoadingStatePresenter;
 import io.realm.Realm;
-import io.realm.RealmChangeListener;
 import io.realm.RealmObject;
 import io.realm.RealmResults;
 
@@ -41,22 +39,18 @@ public void onViewAttached(ProfileView v) {
             requestUser(false);
         }
 
-        userPromise = userManager.getUser(realm, new RealmChangeListener<User>() {
-            @Override
-            public void onChange(User u) {
-                user = u;
-                profile = Profile.get(user.profileId);
+        userPromise = userManager.getUser(realm, (u) -> {
+            user = u;
+            profile = Profile.get(user.profileId);
 
-                getViewOrThrow().showContent();
-                getViewOrThrow().showUser(user, profile);
+            if (isViewAttached()) {
+                getView().showContent();
+                getView().showUser(user, profile);
             }
         });
 
-        enrollmentListPromise = courseManager.listEnrollments(realm, new RealmChangeListener<RealmResults<Enrollment>>() {
-            @Override
-            public void onChange(RealmResults<Enrollment> enrollments) {
-                getViewOrThrow().showEnrollmentCount(enrollments.size());
-            }
+        enrollmentListPromise = courseManager.listEnrollments(realm, (enrollments) -> {
+            if (isViewAttached()) getView().showEnrollmentCount(enrollments.size());
         });
     }
 
diff --git a/build.gradle b/build.gradle
index 9959382d5..b0e8fc2fa 100644
--- a/build.gradle
+++ b/build.gradle
@@ -23,9 +23,9 @@ buildscript {
     dependencies {
         classpath 'com.android.tools.build:gradle:3.1.2'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}"
-        classpath "com.google.gms:google-services:3.3.0"
-        classpath "io.fabric.tools:gradle:1.25.1"
-        classpath "io.realm:realm-gradle-plugin:5.1.0"
+        classpath "com.google.gms:google-services:4.0.1"
+        classpath "io.fabric.tools:gradle:1.25.4"
+        classpath "io.realm:realm-gradle-plugin:5.2.0"
     }
 }
 
diff --git a/lanalytics/build.gradle b/lanalytics/build.gradle
index 1e04a6424..f6789594b 100644
--- a/lanalytics/build.gradle
+++ b/lanalytics/build.gradle
@@ -19,5 +19,5 @@ android {
 
 dependencies {
     implementation 'com.squareup.okhttp3:okhttp:3.10.0'
-    implementation 'com.google.code.gson:gson:2.8.4'
+    implementation 'com.google.code.gson:gson:2.8.5'
 }