title: Failed to resolve attribute at index 13 at android.content.res.TypedArray.getDrawable()
body: <p>My android app runs on a sdk 23 emulator just perfectly, but when I tried to run it on a tablet with sdk version 21, I got this exception:</p>
  
  <pre><code>  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.detactapp.detactapp/com.example.detactapp.detactapp.Home}: java.lang.RuntimeException: Failed to resolve attribute at index 13
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
              at android.app.ActivityThread.access$800(ActivityThread.java:144)
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
              at android.os.Handler.dispatchMessage(Handler.java:102)
              at android.os.Looper.loop(Looper.java:135)
              at android.app.ActivityThread.main(ActivityThread.java:5221)
              at java.lang.reflect.Method.invoke(Native Method)
              at java.lang.reflect.Method.invoke(Method.java:372)
              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
       Caused by: java.lang.RuntimeException: Failed to resolve attribute at index 13
              at android.content.res.TypedArray.getDrawable(TypedArray.java:747)
              at android.view.View.&lt;init&gt;(View.java:3730)
              at android.widget.ImageView.&lt;init&gt;(ImageView.java:139)
              at android.widget.ImageButton.&lt;init&gt;(ImageButton.java:86)
              at android.widget.ImageButton.&lt;init&gt;(ImageButton.java:82)
              at android.support.v7.widget.Toolbar.ensureNavButtonView(Toolbar.java:1036)
              at android.support.v7.widget.Toolbar.setNavigationOnClickListener(Toolbar.java:826)
              at android.support.v7.widget.ToolbarWidgetWrapper.&lt;init&gt;(ToolbarWidgetWrapper.java:188)
              at android.support.v7.widget.ToolbarWidgetWrapper.&lt;init&gt;(ToolbarWidgetWrapper.java:91)
              at android.support.v7.app.ToolbarActionBar.&lt;init&gt;(ToolbarActionBar.java:73)
              at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:205)
              at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:99)
              at com.example.detactapp.detactapp.Home.onCreate(Home.java:32)
              at android.app.Activity.performCreate(Activity.java:5937)
              at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
              at android.app.ActivityThread.access$800(ActivityThread.java:144)
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
              at android.os.Handler.dispatchMessage(Handler.java:102)
              at android.os.Looper.loop(Looper.java:135)
              at android.app.ActivityThread.main(ActivityThread.java:5221)
              at java.lang.reflect.Method.invoke(Native Method)
              at java.lang.reflect.Method.invoke(Method.java:372)
              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
  </code></pre>
  
  <p>This is my build.gradle:</p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:1.2.3'
      }
  }
  apply plugin: 'com.android.application'
  
  repositories {
      jcenter()
  }
  
  android {
      compileSdkVersion 23
      buildToolsVersion "23.0.2"
  
      defaultConfig {
          applicationId "com.example.detactapp.detactapp"
          minSdkVersion 21
          targetSdkVersion 23
          versionCode 1
          versionName "0.1"
      }
  
      compileOptions {
          sourceCompatibility JavaVersion.VERSION_1_6
          targetCompatibility JavaVersion.VERSION_1_6
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      compile 'com.android.support:recyclerview-v7:23.1.1'
      compile 'com.android.support:appcompat-v7:23.1.1'
      compile 'com.android.support:support-v4:23.1.1'
      compile 'com.jjoe64:graphview:4.0.1'
  }
  </code></pre>
  
  <p>And this my Home.java:</p>
  
  <pre><code>public class Home extends AppCompatActivity {
      ...
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_home);
  
          toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar); //Exception throws here
      }
  </code></pre>
  
  <p>And the layout files for the activity:
  At first the navigation drawer activity_home.xml:</p>
  
  <pre><code>&lt;android.support.v4.widget.DrawerLayout
          xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools"
          android:id="@+id/drawer_layout"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          tools:context=".Home"&gt;
  
      &lt;include layout="@layout/home"/&gt;
  
      &lt;android.support.v7.widget.RecyclerView
              xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/views_list"
              android:layout_width="280dp"
              android:layout_height="match_parent"
              android:layout_gravity="start"
              android:choiceMode="singleChoice"
              android:scrollbars="vertical"
              android:background="@android:color/white"&gt;
      &lt;/android.support.v7.widget.RecyclerView&gt;
  &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p>home.xml:</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"&gt;
  
      &lt;include layout="@layout/toolbar"/&gt;
  
      &lt;ScrollView android:layout_width="match_parent"
                  android:layout_height="match_parent"
                  android:layout_below="@+id/toolbar"&gt;
          &lt;LinearLayout android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:id="@+id/container_frame"
                        android:orientation="vertical"
                        android:clipToPadding="false"/&gt;
      &lt;/ScrollView &gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>And toolbar.xml:</p>
  
  <pre><code>&lt;android.support.v7.widget.Toolbar
          xmlns:android="http://schemas.android.com/apk/res/android"
          android:id="@+id/toolbar"
          android:layout_width="match_parent"
          android:layout_height="?attr/actionBarSize"
          android:background="@color/colorPrimary"
          android:elevation="4dp"
          android:theme="@style/DetactTheme"&gt;
  &lt;/android.support.v7.widget.Toolbar&gt;
  </code></pre>
  
  <p>If anyone knows the solution to this problem, I'd love to hear about it :) Thank you!</p>