title: Failed to load AppCompat ActionBar with unknown error in android studio
body: <p>Below is my xml file. In preview there is two error'Failed to load AppCompat ActionBar with unknown error' &amp; 'Failed to instaniate more than one class'. How ever am able to run the app.But the app crashes and in Logcat no errors are shown. </p>
  
  <p>This is my preview screen shot<a href="https://i.stack.imgur.com/6zi7n.png" rel="noreferrer"><img src="https://i.stack.imgur.com/6zi7n.png" alt="enter image description here"></a></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;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"&gt;
  
  
      &lt;include
          layout="@layout/app_bar_main"
          android:layout_width="match_parent"
          android:layout_height="506dp" /&gt;
  
      &lt;LinearLayout
          android:id="@+id/layout_main"
          android:orientation="vertical"
          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:layout_width="match_parent"
          android:layout_height="match_parent"
          android:weightSum="1"
          tools:context=".Activity.MainActivity"&gt;
  
  
      &lt;LinearLayout
          android:id="@+id/main_layout"
          android:orientation="vertical"
          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:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_weight="0.7"
          tools:context=".Activity.MainActivity"&gt;
  
          &lt;!-- our tablayout to display tabs  --&gt;
          &lt;android.support.design.widget.TabLayout
              android:id="@+id/tabLayout"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="50dp"
              app:tabMode="scrollable"
              app:tabSelectedTextColor="@color/colorBlack"
              app:tabTextColor="@color/colorWhite"
              android:background="@color/colorOran"
              android:minHeight="?attr/actionBarSize"
              /&gt;
  
          &lt;!-- View pager to swipe views --&gt;
          &lt;android.support.v4.view.ViewPager
              android:id="@+id/pager"
              android:layout_width="match_parent"
              android:layout_height="match_parent"/&gt;
  
      &lt;/LinearLayout&gt;
  
          &lt;LinearLayout
              android:id="@+id/ll"
              android:layout_width="match_parent"
              android:layout_height="64dp"
              android:layout_alignParentBottom="true"
              android:background="#ffffff"
              android:orientation="horizontal"
              android:layout_weight="0.3"
              android:weightSum="4"
              tools:layout_editor_absoluteX="8dp"
              android:layout_marginBottom="8dp"
              android:layout_alignParentLeft="true"
              android:layout_alignParentStart="true"&gt;
  
              &lt;ImageView
                  android:id="@+id/btn_home"
                  android:layout_width="wrap_content"
                  android:layout_height="match_parent"
                  android:layout_weight="1"
                  android:src="@drawable/ta_home_icon"
                  android:background="@color/colorOran"
                  android:layout_marginRight="1dp"
                  android:scaleType="fitCenter"/&gt;
  
              &lt;ImageView
                  android:id="@+id/btn_new"
                  android:layout_width="wrap_content"
                  android:layout_height="match_parent"
                  android:layout_weight="1"
                  android:src="@drawable/ta_todaydeals_icon"
                  android:background="@color/colorOran"
                  android:layout_marginRight="1dp"
                  android:scaleType="fitCenter"/&gt;
  
              &lt;ImageView
                  android:id="@+id/btn_fav"
                  android:layout_width="wrap_content"
                  android:layout_height="match_parent"
                  android:layout_weight="1"
                  android:src="@drawable/ta_fav_icon"
                  android:background="@color/colorOran"
                  android:layout_marginRight="1dp"
                  android:scaleType="fitCenter"/&gt;
  
              &lt;ImageView
                  android:id="@+id/btn_auth"
                  android:layout_width="wrap_content"
                  android:layout_height="match_parent"
                  android:layout_weight="1"
                  android:src="@drawable/ta_franchie_icon"
                  android:background="@color/colorOran"
                  android:scaleType="fitCenter"
                  android:layout_marginRight="1dp"
                  /&gt;
  
          &lt;/LinearLayout&gt;
  
      &lt;/LinearLayout&gt;
  
  
      &lt;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" /&gt;
  
  
  &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p>Below is appbar_main</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.design.widget.CoordinatorLayout 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:layout_width="match_parent"
      android:layout_height="match_parent"
      tools:context="com.jeyashri.kitchen.jeyashriskitchen.Activity.MainActivity"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:theme="@style/AppTheme.AppBarOverlay"&gt;
  
  
          &lt;android.support.v7.widget.Toolbar
              android:id="@+id/toolbar"
              android:layout_width="match_parent"
              android:layout_height="?attr/actionBarSize"
              android:background="@color/colorOran"
              app:popupTheme="@style/AppTheme.PopupOverlay"&gt;
  
              &lt;ImageView
                  android:id="@+id/app_logo"
                  android:layout_width="80dp"
                  android:layout_height="match_parent"
                  android:src="@drawable/img"/&gt;
  
              &lt;ImageView
                  android:id="@+id/btn_social"
                  android:layout_width="75dp"
                  android:layout_height="35dp"
                  android:layout_marginRight="1dp"
                  android:src="@drawable/share_icon" /&gt;
  
      &lt;/android.support.v7.widget.Toolbar&gt;
  
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;include layout="@layout/content_main" /&gt;
  
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>