@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); getSupportActionBar().setDisplayShowHomeEnabled(true); RealmConfiguration realmConfig = new RealmConfiguration.Builder(this).build(); Realm.deleteRealm(realmConfig); // Remember to remove Realm.setDefaultConfiguration(realmConfig); realm = Realm.getInstance(realmConfig); // DO NOT TOUCH!!! if you want realm to work... drawerFragment = (FragmentDrawer) getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer); drawerFragment.setUp( R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout), toolbar); drawerFragment.setDrawerListener(this); // display the first navigation drawer view on app launch displayView(0); }