title: Unable to start activity ComponentInfo: Error inflating class android.support.design.widget.CoordinatorLayout
body: <p>I am getting this error, could you help me please.</p>
  
  <pre><code>Unable to start activity ComponentInfo
  {com.kaniar.tappy_defender/com.kaniar.tappy_defender.MainActivity}: 
  android.view.InflateException: 
  Binary XML file line #2: 
  Error inflating class android.support.design.widget.CoordinatorLayout
  </code></pre>
  
  <p>MainActivity.java</p>
  
  <pre><code>package com.kaniar.tappy_defender;
  
  import android.app.Activity;
  import android.content.Intent;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.Button;
  
  public class MainActivity extends Activity implements View.OnClickListener {
  
  // This is the entry point of the game
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
  
      // Set the UI layout as the view
      setContentView(R.layout.activity_main);
  
      // Get a reference to the playButton in the layout
      final Button playButton = (Button)findViewById(R.id.playButton);
  
      // Listen for clicks
      playButton.setOnClickListener(this);
  }
  
  @Override
  public void onClick(View v) {
      // Must be the Play button
      // Create a new Intent object
      Intent intent = new Intent(this, GameActivity.class);
  
      // Start the GameActivity class via the Intent
      startActivity(intent);
  
      // Now shut this activity down
      finish();
  }
  }
  </code></pre>
  
  <p>XML file</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"
  android:fitsSystemWindows="true"
  tools:context="com.kaniar.tappy_defender.MainActivity"
  android:background="@drawable/background"&gt;
  
  &lt;include layout="@layout/content_main" /&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>
  
  <p>LogCat output</p>
  
  <pre><code>02-11 18:24:07.980 21999-21999/com.kaniar.tappy_defender E/AndroidRuntime: FATAL EXCEPTION: main
                                                                             Process: com.kaniar.tappy_defender, PID: 21999
                                                                         java.lang.RuntimeException: Unable to start activity ComponentInfo{com.kaniar.tappy_defender/com.kaniar.tappy_defender.MainActivity}: android.view.InflateException: Binary XML file line #2: Error inflating class android.support.design.widget.CoordinatorLayout
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2377)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429)
                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:151)
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342)
                                                                             at android.os.Handler.dispatchMessage(Handler.java:110)
                                                                             at android.os.Looper.loop(Looper.java:193)
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5333)
                                                                             at java.lang.reflect.Method.invokeNative(Native Method)
                                                                             at java.lang.reflect.Method.invoke(Method.java:515)
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
                                                                             at dalvik.system.NativeStart.main(Native Method)
                                                                          Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class android.support.design.widget.CoordinatorLayout
                                                                             at android.view.LayoutInflater.createView(LayoutInflater.java:620)
                                                                             at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:469)
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
                                                                             at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:341)
                                                                             at android.app.Activity.setContentView(Activity.java:1948)
                                                                             at com.kaniar.tappy_defender.MainActivity.onCreate(MainActivity.java:17)
                                                                             at android.app.Activity.performCreate(Activity.java:5343)
                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088)
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429) 
                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:151) 
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) 
                                                                             at android.os.Handler.dispatchMessage(Handler.java:110) 
                                                                             at android.os.Looper.loop(Looper.java:193) 
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5333) 
                                                                             at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                             at java.lang.reflect.Method.invoke(Method.java:515) 
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824) 
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640) 
                                                                             at dalvik.system.NativeStart.main(Native Method) 
                                                                          Caused by: java.lang.reflect.InvocationTargetException
                                                                             at java.lang.reflect.Constructor.constructNative(Native Method)
                                                                             at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
                                                                             at android.view.LayoutInflater.createView(LayoutInflater.java:594)
                                                                             at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696) 
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:469) 
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:397) 
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:353) 
                                                                             at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:341) 
                                                                             at android.app.Activity.setContentView(Activity.java:1948) 
                                                                             at com.kaniar.tappy_defender.MainActivity.onCreate(MainActivity.java:17) 
                                                                             at android.app.Activity.performCreate(Activity.java:5343) 
                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088) 
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331) 
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429) 
                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:151) 
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) 
                                                                             at android.os.Handler.dispatchMessage(Handler.java:110) 
                                                                             at android.os.Looper.loop(Looper.java:193) 
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5333) 
                                                                             at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                             at java.lang.reflect.Method.invoke(Method.java:515) 
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824) 
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640) 
                                                                             at dalvik.system.NativeStart.main(Native Method) 
                                                                          Caused by: java.lang.IllegalArgumentException: You need to use a Theme.AppCompat theme (or descendant) with the design library.
                                                                             at android.support.design.widget.ThemeUtils.checkAppCompatTheme(ThemeUtils.java:34)
                                                                             at android.support.design.widget.CoordinatorLayout.&lt;init&gt;(CoordinatorLayout.java:178)
                                                                             at android.support.design.widget.CoordinatorLayout.&lt;init&gt;(CoordinatorLayout.java:172)
                                                                             at java.lang.reflect.Constructor.constructNative(Native Method) 
                                                                             at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 
                                                                             at android.view.LayoutInflater.createView(LayoutInflater.java:594) 
                                                                             at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696) 
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:469) 
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:397) 
                                                                             at android.view.LayoutInflater.inflate(LayoutInflater.java:353) 
                                                                             at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:341) 
                                                                             at android.app.Activity.setContentView(Activity.java:1948) 
                                                                             at com.kaniar.tappy_defender.MainActivity.onCreate(MainActivity.java:17) 
                                                                             at android.app.Activity.performCreate(Activity.java:5343) 
                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088) 
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331) 
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429) 
                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:151) 
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) 
                                                                             at android.os.Handler.dispatchMessage(Handler.java:110) 
                                                                             at android.os.Looper.loop(Looper.java:193) 
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5333) 
                                                                             at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                             at java.lang.reflect.Method.invoke(Method.java:515)
  </code></pre>
  
  <p>I don't really know what happens, I can build the project but when I run the app on a phone or a simulator, I got this !
  If someone know a solution, it will be awesome !</p>