diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index a0b87c7..dd21ef1 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="fr.unix_experience.owncloud_sms"
-    android:versionCode="22"
-    android:versionName="0.17.3">
+    android:versionCode="24"
+    android:versionName="0.18.1">
 
     <!-- From Android 4.0 to 5.1 -->
     <uses-sdk
diff --git a/src/fr/unix_experience/owncloud_sms/activities/MainActivity.java b/src/fr/unix_experience/owncloud_sms/activities/MainActivity.java
index e1c727f..0ab7410 100644
--- a/src/fr/unix_experience/owncloud_sms/activities/MainActivity.java
+++ b/src/fr/unix_experience/owncloud_sms/activities/MainActivity.java
@@ -33,6 +33,7 @@ import org.json.JSONArray;
 import android.app.Activity;
 import android.app.Fragment;
 import android.app.FragmentManager;
+import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -43,6 +44,7 @@ import android.support.v4.view.ViewPager;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 import fr.unix_experience.owncloud_sms.R;
 import fr.unix_experience.owncloud_sms.engine.ASyncTask.SyncTask;
 import fr.unix_experience.owncloud_sms.engine.ConnectivityMonitor;
@@ -160,19 +162,23 @@ public class MainActivity extends Activity {
 	}
 
 	public void syncAllMessages(final View view) {
-		final ConnectivityMonitor cMon = new ConnectivityMonitor(getApplicationContext());
+		final Context ctx = getApplicationContext();
+		final ConnectivityMonitor cMon = new ConnectivityMonitor(ctx);
 
 		if (cMon.isValid()) {
 			// Now fetch messages since last stored date
-			final JSONArray smsList = new SmsFetcher(getApplicationContext())
+			final JSONArray smsList = new SmsFetcher(ctx)
 			.bufferizeMessagesSinceDate((long) 0);
 
 			if (smsList != null) {
-				final OCSMSNotificationManager nMgr = new OCSMSNotificationManager(getApplicationContext());
+				final OCSMSNotificationManager nMgr = new OCSMSNotificationManager(ctx);
 				nMgr.setSyncProcessMsg();
 				new SyncTask(getApplicationContext(), smsList).execute();
 			}
 		}
+		else {
+			Toast.makeText(ctx, ctx.getString(R.string.err_sync_no_connection_available), Toast.LENGTH_SHORT).show();
+		}
 	}
 
 	public void openGooglePlayStore(final View view) {
diff --git a/src/fr/unix_experience/owncloud_sms/engine/ConnectivityMonitor.java b/src/fr/unix_experience/owncloud_sms/engine/ConnectivityMonitor.java
index fbc869f..3882457 100644
--- a/src/fr/unix_experience/owncloud_sms/engine/ConnectivityMonitor.java
+++ b/src/fr/unix_experience/owncloud_sms/engine/ConnectivityMonitor.java
@@ -12,36 +12,39 @@ package fr.unix_experience.owncloud_sms.engine;
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU Affero General Public License for more details.
- *  
+ *
  *  You should have received a copy of the GNU Affero General Public License
- */ 
+ */
 
-import fr.unix_experience.owncloud_sms.prefs.OCSMSSharedPrefs;
 import android.content.Context;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.telephony.TelephonyManager;
+import fr.unix_experience.owncloud_sms.prefs.OCSMSSharedPrefs;
 
 public class ConnectivityMonitor {
-	public ConnectivityMonitor(Context context) {
+	public ConnectivityMonitor(final Context context) {
 		_context = context;
 	}
-	
+
 	// Valid connection = WiFi or Mobile data
 	public boolean isValid() {
 		if (_cMgr == null) {
 			_cMgr = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
-		}		
-		
+		}
+
 		final android.net.NetworkInfo niWiFi = _cMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
 		final android.net.NetworkInfo niMobile = _cMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
-		
+
 		if (niWiFi.isAvailable() || niMobile.isAvailable()) {
 			// Load the connectivity manager to determine on which network we are connected
-			NetworkInfo netInfo = _cMgr.getActiveNetworkInfo();
-			
-			OCSMSSharedPrefs prefs = new OCSMSSharedPrefs(_context);
-			
+			final NetworkInfo netInfo = _cMgr.getActiveNetworkInfo();
+			if (netInfo == null) {
+				return false;
+			}
+
+			final OCSMSSharedPrefs prefs = new OCSMSSharedPrefs(_context);
+
 			// Check
 			switch (netInfo.getType()) {
 			case ConnectivityManager.TYPE_WIFI:
@@ -58,7 +61,7 @@ public class ConnectivityMonitor {
 				case TelephonyManager.NETWORK_TYPE_HSDPA:
 				case TelephonyManager.NETWORK_TYPE_HSPA:
 				case TelephonyManager.NETWORK_TYPE_HSUPA:
-				case TelephonyManager.NETWORK_TYPE_UMTS:	
+				case TelephonyManager.NETWORK_TYPE_UMTS:
 				case TelephonyManager.NETWORK_TYPE_EHRPD:
 				case TelephonyManager.NETWORK_TYPE_EVDO_B:
 				case TelephonyManager.NETWORK_TYPE_HSPAP:
@@ -71,13 +74,11 @@ public class ConnectivityMonitor {
 			default:
 				return prefs.syncInOtherModes();
 			}
-			
-			
 		}
-		
+
 		return false;
 	}
-	
+
 	private ConnectivityManager _cMgr;
-	private Context _context;
+	private final Context _context;
 }