diff --git a/app/src/androidTest/java/it/reyboz/bustorino/data/gtfs/ParcelableTest.java b/app/src/androidTest/java/it/reyboz/bustorino/data/gtfs/ParcelableTest.java
new file mode 100644
--- /dev/null
+++ b/app/src/androidTest/java/it/reyboz/bustorino/data/gtfs/ParcelableTest.java
@@ -0,0 +1,64 @@
+package it.reyboz.bustorino.data.gtfs;
+
+import android.os.Parcel;
+import it.reyboz.bustorino.backend.Palina;
+import it.reyboz.bustorino.backend.Passaggio;
+import it.reyboz.bustorino.backend.Route;
+import it.reyboz.bustorino.backend.Stop;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ParcelableTest {
+
+    @Test
+    public void testPalinaParcelableTransfer() {
+
+        Palina p = new Palina("32", "TestPalina", "myname", "Via madre di dio", 9.211,-8.92, "gtt:none");
+        ArrayList<Passaggio> pass1,pass2;
+        pass1 = new ArrayList<>();
+        pass2 = new ArrayList<>();
+        for (int i = 0; i < 4; i++) {
+            pass1.add(Passaggio.newInstance(20, 9+5*i,true, Passaggio.Source.MatoAPI, 0));
+            pass1.add(Passaggio.newInstance(20, 9+7*i,true, Passaggio.Source.MatoAPI, 0));
+        }
+        Route r;
+        r= new Route("Mas","destinazione",pass1,Route.Type.BUS,"maiam");
+        p.addRoute(r);
+        r = new Route("18","Max",pass2,Route.Type.TRAM,"descr");
+        p.addRoute(r);
+
+        Parcel parcel = Parcel.obtain();
+        p.writeToParcel(parcel, p.describeContents());
+
+        parcel.setDataPosition(0);
+
+        Palina p2 =  Palina.CREATOR.createFromParcel(parcel);
+
+        parcel.recycle();
+
+        assertEquals(p2.ID, p.ID);
+        assertEquals(p2.gtfsID, p.gtfsID);
+        assertEquals(p.location, p2.location);
+        assertEquals("Via madre di dio", p.location);
+        assertEquals(p.type, p2.type);
+        assertEquals(p.getLatitude(),p2.getLatitude());
+        assertEquals(p.getLongitude(),p2.getLongitude());
+        assertEquals(p.getTotalNumberOfPassages(),p2.getTotalNumberOfPassages());
+        List<Route> rl1, rl2;
+        rl1 = p.queryAllRoutes();
+        rl2 = p.queryAllRoutes();
+        assertEquals(rl1.size(), rl2.size());
+        Route x,y;
+        for (int i = 0; i < rl1.size(); i++) {
+            x = rl1.get(i);
+            y = rl2.get(i);
+            assertEquals(x.destinazione,y.destinazione);
+            assertEquals(x.type,y.type);
+            assertEquals(x.description,y.description);
+            assertEquals(x.getPassaggiToString(),y.getPassaggiToString());
+        }
+    }
+}
diff --git a/app/src/main/java/it/reyboz/bustorino/backend/Palina.java b/app/src/main/java/it/reyboz/bustorino/backend/Palina.java
--- a/app/src/main/java/it/reyboz/bustorino/backend/Palina.java
+++ b/app/src/main/java/it/reyboz/bustorino/backend/Palina.java
@@ -26,11 +26,9 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.List;
 
 import it.reyboz.bustorino.util.LinesNameSorter;
@@ -500,7 +498,7 @@
     }
 
     @Override
-    public void writeToParcel(Parcel dest, int flags) {
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
         super.writeToParcel(dest, flags);
         dest.writeTypedList(routes);
         dest.writeByte((byte) (routesModified ? 1 : 0));
diff --git a/app/src/main/java/it/reyboz/bustorino/data/AppDataProvider.java b/app/src/main/java/it/reyboz/bustorino/data/AppDataProvider.java
--- a/app/src/main/java/it/reyboz/bustorino/data/AppDataProvider.java
+++ b/app/src/main/java/it/reyboz/bustorino/data/AppDataProvider.java
@@ -21,9 +21,11 @@
 import android.database.Cursor;
 import android.database.sqlite.SQLiteConstraintException;
 import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteDatabaseLockedException;
 import android.net.Uri;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
 import it.reyboz.bustorino.BuildConfig;
 import it.reyboz.bustorino.backend.DBStatusManager;
 import it.reyboz.bustorino.backend.Stop;
@@ -204,6 +206,7 @@
     }
 
     @Override
+    @Nullable
     public Cursor query(Uri uri, String[] projection, String selection,
                         String[] selectionArgs, String sortOrder) throws UnsupportedOperationException,IllegalArgumentException {
         //IMPORTANT
@@ -211,7 +214,15 @@
         if(preferences.isDBUpdating(true))
             //throw new UnsupportedOperationException("DB is updating");
             return null;
-        SQLiteDatabase  db = appDBHelper.getReadableDatabase();
+        SQLiteDatabase db;
+        try{
+            //try to get a readable database
+            db = appDBHelper.getReadableDatabase();
+        } catch (SQLiteDatabaseLockedException ex){
+            Log.e(DEBUG_TAG,"Database is locked",ex);
+            return null;
+        }
+
         List<String>  parts = uri.getPathSegments();
         switch (sUriMatcher.match(uri)){
             case LOCATION_SEARCH:
diff --git a/app/src/main/java/it/reyboz/bustorino/fragments/FragmentHelper.java b/app/src/main/java/it/reyboz/bustorino/fragments/FragmentHelper.java
--- a/app/src/main/java/it/reyboz/bustorino/fragments/FragmentHelper.java
+++ b/app/src/main/java/it/reyboz/bustorino/fragments/FragmentHelper.java
@@ -253,7 +253,7 @@
     public void showToastMessage(int messageID, boolean short_lenght) {
         final int length = short_lenght ? Toast.LENGTH_SHORT : Toast.LENGTH_LONG;
         if (context != null)
-        Toast.makeText(context, messageID, length).show();
+            Toast.makeText(context, messageID, length).show();
     }
     private void showShortToast(int messageID){
         showToastMessage(messageID, true);