diff --git a/BeWoPlanerChat/bewoplaner-chat-android/app/build.gradle b/BeWoPlanerChat/bewoplaner-chat-android/app/build.gradle
index 35717cc..5bc347d 100644
--- a/BeWoPlanerChat/bewoplaner-chat-android/app/build.gradle
+++ b/BeWoPlanerChat/bewoplaner-chat-android/app/build.gradle
@@ -33,8 +33,8 @@ android {
         applicationId "de.beyondsoft.ownchat"
         minSdkVersion 19
         targetSdkVersion 27
-        versionCode 23
-        versionName "1.23"
+        versionCode 24
+        versionName "1.24"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         multiDexEnabled true
     }
diff --git a/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/data/firebase/HandleMessagesService.java b/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/data/firebase/HandleMessagesService.java
index 22e71de..20a2b5b 100644
--- a/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/data/firebase/HandleMessagesService.java
+++ b/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/data/firebase/HandleMessagesService.java
@@ -46,7 +46,6 @@ import android.support.v4.app.NotificationCompat;
 import android.support.v4.app.RemoteInput;
 import android.support.v4.content.ContextCompat;
 import android.text.TextUtils;
-import android.util.Log;
 
 import java.io.IOException;
 import java.net.HttpURLConnection;
@@ -76,23 +75,10 @@ public class HandleMessagesService extends FirebaseMessagingService {
     @Named(AppPrefsConstants.USER_ID)
     LongPreference mUserIdReference;
 
-    @Override
-    public void onDeletedMessages() {
-        Utils.makeFirebaseLogEntry("onDeletedMessages. Possible reasons:\n" +
-                "    Too many messages stored on the FCM server. This can occur when an app's servers send a bunch of non-collapsible messages to FCM servers while the device is offline.\n" +
-                "    The device hasn't connected in a long time and the app server has recently (within the last 4 weeks) sent a message to the app on that device.");
-
-        super.onDeletedMessages();
-    }
-
     @Override
     public void onMessageReceived(RemoteMessage remoteMessage) {
-        Log.i("FIREBASE_RECEIVER", "onMessageReceived called");
-
         Map<String, String> dataMap = remoteMessage.getData();
 
-        Utils.makeFirebaseLogEntry("onMessageReceived: " + dataMap.get(Constants.MESSAGE_ID));
-
         InjectionHelper.getMessagingComponent(this).inject(HandleMessagesService.this);
 
         customizeNotification(dataMap);
@@ -101,8 +87,6 @@ public class HandleMessagesService extends FirebaseMessagingService {
     private void customizeNotification(Map<String, String> dataMap) {
         String messageId = dataMap.get(Constants.MESSAGE_ID);
 
-        Utils.makeFirebaseLogEntry("customizeNotification for message " + messageId);
-
         mChatService.getMessage(messageId)
                 .compose(RxUtils.provideDefaultTransformer())
                 .flatMap(new ErrorHandlingResponseConverter<>())
@@ -112,9 +96,6 @@ public class HandleMessagesService extends FirebaseMessagingService {
 
     @SuppressLint("StaticFieldLeak")
     private void getMessageSuccess(Message message) {
-        Log.i("FIREBASE_RECEIVER", "Message received");
-        Utils.makeFirebaseLogEntry("getMessageSuccess called for message " + message.id);
-
         Bundle bundle = new Bundle();
 
         bundle.putString(Constants.MESSAGE_ID, message.id);
@@ -141,7 +122,7 @@ public class HandleMessagesService extends FirebaseMessagingService {
                         public void onReceive(Context context, Intent intent) {
                             Bundle results = getResultExtras(true);
 
-                            if (!results.getBoolean(CHAT_IS_ALREADY_OPEN, false)) {
+                            if(!results.getBoolean(CHAT_IS_ALREADY_OPEN, false)) {
                                 int groupId = (int) bundle.getLong(Constants.GROUP_ID);
                                 int numberOfUsers = message.numberOfGroupUsers;
                                 intent = MainActivity.createIntent(context, bundle, numberOfUsers, groupId);
@@ -149,7 +130,7 @@ public class HandleMessagesService extends FirebaseMessagingService {
                                 PendingIntent pendingIntent = PendingIntent.getActivity(context, groupId, intent, PendingIntent.FLAG_UPDATE_CURRENT);
 
                                 Bitmap bitmapToDisplay = bitmap;
-                                if (bitmapToDisplay == null) {
+                                if(bitmapToDisplay == null) {
                                     bitmapToDisplay = BitmapFactory.decodeResource(context.getResources(), R.drawable.avatar);
                                 }
 
@@ -227,15 +208,13 @@ public class HandleMessagesService extends FirebaseMessagingService {
                         }
                     }, null, Activity.RESULT_OK, null, null);
                 }
-            }.execute(new URL(message.senderAvatar));
+            }.execute((Utils.isNullOrEmpty(message.senderAvatar) ? null : new URL(message.senderAvatar)));
         } catch(MalformedURLException e) {
-            Utils.makeFirebaseLogEntry("Exception in getMessageSuccess (" + message.id + ")" + e.toString());
             e.printStackTrace();
         }
     }
 
     private void getMessageError(Throwable throwable) {
-        Utils.makeFirebaseLogEntry("getMessageError " + throwable.getMessage());
         throwable.printStackTrace();
     }
 
@@ -275,7 +254,7 @@ public class HandleMessagesService extends FirebaseMessagingService {
     }
 
     private String setNotificationTitle(Message message, int numberOfUsers) {
-        if (numberOfUsers > 2) {
+        if(numberOfUsers > 2) {
             return message.senderName + " @ " + message.groupName;
         } else {
             return message.senderName;
@@ -283,7 +262,7 @@ public class HandleMessagesService extends FirebaseMessagingService {
     }
 
     private NotificationCompat.Action createAction(Context context, int noOfUsers, int groupId, Bundle bundle) {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
+        if(Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
             return null;
         }
 
@@ -353,7 +332,7 @@ public class HandleMessagesService extends FirebaseMessagingService {
     private static class DownloadAvatarTask extends AsyncTask<URL, Void, Bitmap> {
         @Override
         protected Bitmap doInBackground(URL... urls) {
-            if(urls == null || urls.length == 0) {
+            if(urls == null || urls.length == 0 || urls[0] == null) {
                 return null;
             }
 
diff --git a/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/utils/Utils.java b/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/utils/Utils.java
index 29ba0c8..3dcc75d 100644
--- a/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/utils/Utils.java
+++ b/BeWoPlanerChat/bewoplaner-chat-android/app/src/main/java/de/beyondsoft/ownchat/utils/Utils.java
@@ -231,4 +231,8 @@ public class Utils {
 
         return calendar1.before(calendar2);
     }
+
+    public static boolean isNullOrEmpty(String string) {
+        return string == null || string.length() == 0;
+    }
 }