title: Error inflating class - NestedScrollView - class not found
body: <p>Running Android Studio 2.1.2, Windows 7.</p>
  
  <p>I replaced a ScrollView with a NestedScrollView and now I'm getting </p>
  
  <blockquote>
    <p>android.view.InflateException: Binary XML file line #2: Error
    inflating class NestedScrollView</p>
    
    <p>java.lang.ClassNotFoundException: Didn't find class
    "android.view.NestedScrollView" on path:
    /data/app/com.assemblyguide.remote-48.apk</p>
  </blockquote>
  
  <p>... when I call SetContentView() on that XML file.  I did not get it when I had just a ScrollView.</p>
  
  <p>I've tried cleaning, and invalidating the cache and rebuilding.  The XML looks like this . . . </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
      android:layout_height="match_parent"
      android:orientation="vertical" &gt;
  
      &lt;!-- This linear layout is because the scrollview can have only 1 direct child --&gt;
      &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:orientation="vertical" &gt;
  
          &lt;!-- Relative layout for Workorder --&gt;
          &lt;RelativeLayout
              android:id="@+id/rellayWorkorder"
              android:background="#383838"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="30dp"
              android:layout_marginBottom="2dp"&gt;
              &lt;TextView
                  android:id="@+id/workorderlabel"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="Work Order:"/&gt;
  
              &lt;TextView
                  android:id="@+id/workorderContent"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight="true"
                  android:layout_margin="2dp"
                  android:gravity="right"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="---workorder---"/&gt;
          &lt;/RelativeLayout&gt;
  
  
          &lt;!-- Relative layout for Required Time
     &lt;FrameLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_gravity="center_horizontal"&gt;&lt;/FrameLayout&gt; --&gt;
  
          &lt;RelativeLayout
              android:id="@+id/rellayRequiredTime"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="30dp"
              android:layout_marginBottom="2dp"&gt;
              &lt;TextView
                  android:id="@+id/requiredTimelabel"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="Required Time:"/&gt;
  
              &lt;TextView
                  android:id="@+id/requiredTimeContent"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight="true"
                  android:layout_margin="2dp"
                  android:gravity="right"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="--- 00 minutes ---"/&gt;
          &lt;/RelativeLayout&gt;
  
          &lt;!-- Relative layout for Time remaining --&gt;
          &lt;RelativeLayout
              android:id="@+id/rellayTimeRemaining"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="30dp"
              android:layout_marginBottom="2dp"&gt;
              &lt;TextView
                  android:id="@+id/timeremaininglabel"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="Time Remaining:"/&gt;
  
              &lt;TextView
                  android:id="@+id/tviewtimeremainingContent"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight="true"
                  android:layout_margin="2dp"
                  android:gravity="right"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="--- 0:00:00---"/&gt;
          &lt;/RelativeLayout&gt;
  
          &lt;!--  Linear layout for Record Start / Record End buttons --&gt;
          &lt;LinearLayout
              android:orientation="horizontal"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="10dp"  &gt;
              &lt;Button
                  android:id="@+id/debulkrecordStart"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_marginTop="6dp"
                  android:layout_marginRight="4dp"
                  android:gravity="center"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:onClick="OnSetRecordStartTimeClick"
                  android:text="Record Start"/&gt;
              &lt;Button
                  android:id="@+id/debulkrecordEnd"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_marginTop="6dp"
                  android:layout_marginRight="4dp"
                  android:gravity="center"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:onClick="OnSetRecordEndTimeClick"
                  android:text="Record End"/&gt;
          &lt;/LinearLayout&gt;
  
          &lt;!-- Relative layout for Vacuum level --&gt;
          &lt;RelativeLayout
              android:id="@+id/rellayvacuumlevel"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginBottom="2dp"&gt;
              &lt;TextView
                  android:id="@+id/vaclabel"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceSmall"
                  android:text="Vacuum Level (inches Hg):"/&gt;
              &lt;EditText
                  android:id="@+id/vacleveledit"
                  android:layout_width="120dp"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight = "true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceSmall"
                  android:inputType="text|textCapCharacters"
                  android:text="vac level"
                  android:layout_marginRight="2dp"
                  android:layout_marginTop="2dp"
                  android:layout_marginBottom="2dp"/&gt;
          &lt;/RelativeLayout&gt;
  
          &lt;!-- Relative layout for Vac Gauge Equipment # --&gt;
          &lt;RelativeLayout
              android:id="@+id/rlayvacuumGauge"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginBottom="2dp"&gt;
              &lt;TextView
                  android:id="@+id/vacgaugelabel"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceSmall"
                  android:text="Vac Gauge Equipment #:"/&gt;
              &lt;EditText
                  android:id="@+id/vacgaugeedit"
                  android:layout_width="120dp"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight = "true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceSmall"
                  android:inputType="text|textCapCharacters"
                  android:text="equip. #"/&gt;
          &lt;/RelativeLayout&gt;
  
  
  
          &lt;!-- Relative layout for Calibration Due date --&gt;
          &lt;RelativeLayout
              android:id="@+id/rlaycalibdue"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginBottom="2dp"&gt;
              &lt;TextView
                  android:id="@+id/calibduelabel"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceSmall"
                  android:text="Calibration Due Date:"/&gt;
              &lt;EditText
                  android:id="@+id/calibdueedit"
                  android:layout_width="120dp"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight = "true"
                  android:layout_margin="2dp"
                  android:gravity="left"
                  android:textAppearance="?android:attr/textAppearanceSmall"
                  android:inputType="text|textCapCharacters"
                  android:text="mm/dd/yyyy"/&gt;
          &lt;/RelativeLayout&gt;
  
  
          &lt;CalendarView
              android:id="@+id/debulkcalendar"
              android:layout_width="300dp"
              android:layout_height="250dp"
              android:minDate="01/01/2016"
              android:maxDate="11/30/2016"
              /&gt;
  
  
          &lt;!--  this linear layout is for the debulk override and done buttons  --&gt;
          &lt;LinearLayout
              android:orientation="horizontal"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="10dp"  &gt;
              &lt;Button
                  android:id="@+id/debulkOverride"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_marginTop="6dp"
                  android:layout_marginRight="4dp"
                  android:onClick="OnResetClick"
                  android:gravity="center"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="Override"/&gt;
              &lt;Button
                  android:id="@+id/debulkDone"
                  android:layout_width="150dp"
                  android:layout_height="wrap_content"
                  android:layout_marginTop="6dp"
                  android:layout_marginRight="2dp"
                  android:onClick="onDoneBtnClick"
                  android:gravity="center"
                  android:textAppearance="?android:attr/textAppearanceMedium"
                  android:text="Done"/&gt;
          &lt;/LinearLayout&gt;
  
      &lt;/LinearLayout&gt;
  
  &lt;/NestedScrollView&gt;
  </code></pre>
  
  <p>What does this error mean and how do I fix it?</p>