我在活动中实现片段，有时它会显示以下错误。当我尝试加载appactivity片段时。请帮我摆脱这个错误

Java.lang.RuntimeException: Unable to start activity       
ComponentInfo{com.example.rff/com.example.rff.Parent}:
android.view.InflateException: Binary XML file line #68: Error inflating class fragment

这是我的xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
android:orientation="vertical" >
    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" 
    android:id="@+id/frag_parent"

    >

<TableLayout
    android:id="@+id/tablenew"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:background="#FFF"
    android:paddingTop="1dp"
    android:stretchColumns="0"

     >

        <TableRow
            android:background="#000000"
            android:paddingBottom="1dp"
            android:paddingRight="1dp"
            android:tag="new">
         <TextView
                android:id="@+id/newactivity"
                android:text="@string/newact"
                android:gravity="center"
                android:layout_marginLeft="1dp"
                android:textColor="#000000"
                android:background="#FFF"
                android:padding="10dp"
                android:textSize="50sp"

            />
        </TableRow>
    </TableLayout>    

</LinearLayout>

<LinearLayout
    android:layout_width="1000dp"
    android:layout_height="50dp">
    <Button 
        android:id="@+id/app_new"
        android:layout_width="420dp"
        android:layout_height="match_parent"
        android:text="Apps"/>

    <Button 
        android:id="@+id/doc_new"
        android:layout_width="400dp"
        android:layout_height="match_parent"
        android:text="Docs"/>

  </LinearLayout>

   <fragment
   class="com.example.rff.AppActivity"
   android:id="@+id/lm_fragment"   
   android:layout_width="0dp"
   android:layout_height="wrap_content" />

 <fragment
 class="com.example.rff.DocActivity"
 android:id="@+id/doc_fragment"   
 android:layout_width="0dp"
 android:layout_height="wrap_content" />
 </LinearLayout>

这是我的父片段活动

FragmentManager fragmentManager = getFragmentManager(); 
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
  AppActivity appActivity = new AppActivity();
   fragmentTransaction.replace(android.R.id.content, appActivity);
  fragmentTransaction.commit();

活跃

public class AppActivity extends Fragment{
Context context;
ArrayList<ViewGroup> viewsList;
UpdateAppThread UpdateThread;
View view;

@Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
      Bundle savedInstanceState) {

      View view = inflater.inflate(R.layout.app_new_layout,container, false);
    context = view.getContext();
    ...
    ....
    return view ;
}