title: Error on displaying the graphical layout for an android app: com.android.layoutlib.bridge.MockView cannot be cast to android.view.ViewGroup
body: <p>I get this error when I switch from XML to GraphicalLayout in Eclipse. This is my code:</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context=".AddPeople" &gt;
  
  &lt;fragment
      android:id="@+id/AddPeopleList"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" &gt;
  
      &lt;EditText
          android:id="@+id/AddPeople_Name"
          android:hint="@string/AddPeople_ETHintName" /&gt;
  
      &lt;EditText
          android:id="@+id/AddPeople_Number"
          android:hint="@string/AddPeople_ETHintNumber" 
          android:inputType="phone" /&gt;
  &lt;/fragment&gt;
  </code></pre>
  
  <p></p>
  
  <p>I've checked through for obvious errors, but haven't spotted any. This is inflated in the normal way in an activity, but I think that problem is in the code. Thanks for the help!!!</p>