CoordinatorLayout + AppBarLayout + NavigationDrawer

Your CoordinatorLayout is wrapping your DrawerLayout and NavigationView, which means the Coordinator is in control of how everything is laid out. You need to nest the Coordinator inside the drawer, like so:

<android.support.v4.widget.DrawerLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/drawer_layout"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:clickable="true"    android:focusableInTouchMode="true">    <android.support.design.widget.CoordinatorLayout        xmlns:app="http://schemas.android.com/apk/res-auto"        android:id="@+id/overview_coordinator_layout"        android:layout_width="match_parent"        android:layout_height="match_parent">        <android.support.design.widget.AppBarLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">            <android.support.v7.widget.Toolbar                android:id="@+id/toolbar"                android:layout_width="match_parent"                android:layout_height="?attr/actionBarSize"                android:background="?attr/colorPrimaryDark"                app:layout_scrollFlags="enterAlways|scroll" />        </android.support.design.widget.AppBarLayout>        <android.support.v4.widget.NestedScrollView            android:layout_width="match_parent"            android:layout_height="wrap_content"            app:layout_behavior="@string/appbar_scrolling_view_behavior">            <TextView                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:text="@string/lorem_ipsum_long" />        </android.support.v4.widget.NestedScrollView>        <android.support.design.widget.FloatingActionButton            android:id="@+id/overview_floating_action_button"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_margin="16dp"            android:clickable="true"            android:src="@drawable/ic_add"            app:layout_anchor="@id/overview_coordinator_layout"            app:layout_anchorGravity="bottom|right|end"            app:layout_behavior="@string/fab_onscroll_behavior" />    </android.support.design.widget.CoordinatorLayout>    <android.support.design.widget.NavigationView        android:id="@+id/nvView"        android:layout_width="wrap_content"        android:layout_height="match_parent"        android:layout_gravity="start"        android:background="@android:color/white"        app:headerLayout="@layout/nav_header"        app:menu="@menu/navigationdrawer_main" /></android.support.v4.widget.DrawerLayout>

That should sort it out!

To add on to the previous answer, you can make the DrawerLayout cleaner by moving the CoordinatorLayout+child elements into a separate xml file. And then just use the "include" option to add the file.

<?xml version="1.0" encoding="utf-8"?><android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"xmlns:tools="http://schemas.android.com/tools"android:id="@+id/drawer_layout"android:layout_width="match_parent"android:layout_height="match_parent"android:fitsSystemWindows="true"tools:openDrawer="start">  <!-- Widget Coordinator + child elements go here -->  <include    layout="@layout/app_bar_main"    android:layout_width="match_parent"    android:layout_height="match_parent" />  <android.support.design.widget.NavigationView    android:id="@+id/nav_view"    android:layout_width="wrap_content"    android:layout_height="match_parent"    android:layout_gravity="start"    android:fitsSystemWindows="true"    app:headerLayout="@layout/nav_header_main"    app:menu="@menu/activity_main_drawer" /></android.support.v4.widget.DrawerLayout>