title: Run the program and on phone it stops because an error has occured
body: <p>This is my program it is just a basic one. I'm trying to make the Start button work. So with me pressing it , it will change the Default Text of Hello World to MP 2014. But it kept giving me error on phone. I tried removing all the buttons and textview related and it worked flawlessly.</p>
  
  <pre><code>package com.example.newapp;
  
  import android.app.Activity;
  import android.app.ActionBar;
  import android.app.Fragment;
  import android.os.Bundle;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.Button;
  import android.widget.TextView;
  import android.os.Build;
  
  public class MainActivity extends Activity {
      Button button1;
          TextView txtChange;
      @Override
              protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
  
  
          txtChange = (TextView) findViewById(R.id.textView1);
          button1 = (Button) findViewById(R.id.button1);
  
          button1.setOnClickListener(new View.OnClickListener() {
  
              @Override
              public void onClick(View v) {
                  txtChange.setText("MP 2014");
              }
          });
  
  
      04-22 12:07:14.056: E/SELinux(17541): selinux_android_seapp_context_reload: seapp_contexts file is loaded from /seapp_contexts
  04-22 12:07:14.336: E/AndroidRuntime(17523): FATAL EXCEPTION: main
  04-22 12:07:14.336: E/AndroidRuntime(17523): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.newapp/com.example.newapp.MainActivity}: java.lang.NullPointerException
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2308)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2362)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.ActivityThread.access$700(ActivityThread.java:168)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1329)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.os.Handler.dispatchMessage(Handler.java:99)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.os.Looper.loop(Looper.java:137)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.ActivityThread.main(ActivityThread.java:5493)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at java.lang.reflect.Method.invokeNative(Native Method)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at java.lang.reflect.Method.invoke(Method.java:525)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at dalvik.system.NativeStart.main(Native Method)
  04-22 12:07:14.336: E/AndroidRuntime(17523): Caused by: java.lang.NullPointerException
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at com.example.newapp.MainActivity.onCreate(MainActivity.java:29)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.Activity.performCreate(Activity.java:5372)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270)
  04-22 12:07:14.336: E/AndroidRuntime(17523):    ... 11 more
  04-22 12:07:14.986: E/BatteryService(2399): Could not open /efs/FactoryApp/batt_cable_count
  04-22 12:07:15.336: E/EnterpriseContainerManager(2399): ContainerPolicy Service is not yet ready!!!
  04-22 12:07:15.346: E/EnterpriseContainerManager(2399): ContainerPolicy Service is not yet ready!!!
  04-22 12:07:15.451: E/SELinux(17570): Function: selinux_android_load_priority [0], There is no sepolicy file 
  04-22 12:07:15.451: E/SELinux(17570):  
  04-22 12:07:15.451: E/SELinux(17570): Function: selinux_android_load_priority [1], There is no sepolicy version file 
  04-22 12:07:15.451: E/SELinux(17570):  
  04-22 12:07:15.451: E/SELinux(17570): Function: selinux_android_load_priority , loading version is VE=SEPF_GT-N7105_4.3_0016
  04-22 12:07:15.451: E/SELinux(17570):  
  04-22 12:07:15.451: E/SELinux(17570):  
  04-22 12:07:15.451: E/SELinux(17570): selinux_android_seapp_context_reload: seapp_contexts file is loaded from /seapp_contexts
  04-22 12:07:15.511: E/android.os.Debug(2399): !@Dumpstate &gt; sdumpstate -k -t -z -d -o /data/log/dumpstate_app_error
  04-22 12:07:15.866: E/Samsung TTS(17570): onIsLanguageAvailable() - lang : eng, country : USA, variant : , iResult : 1
  04-22 12:07:15.866: E/Samsung TTS(17570): onLoadLanguage() - LANG_COUNTRY_AVAILABLE
  04-22 12:07:15.866: E/Samsung TTS(17570): onLoadLanguage() - lang : eng, country : USA, variant : f01
  04-22 12:07:16.031: E/(17570): Samsung TTS Engine - initialize() : Samsung TTS Engine (released - 201302151)
  04-22 12:07:16.031: E/(17570): Samsung TTS Engine - initialize() : ro.product.manufacturer - samsung
  04-22 12:07:16.206: E/Samsung TTS(17570): onIsLanguageAvailable() - lang : eng, country : USA, variant : , iResult : 1
  04-22 12:07:16.206: E/Samsung TTS(17570): onIsLanguageAvailable() - lang : eng, country : USA, variant : , iResult : 1
  04-22 12:07:16.206: E/Samsung TTS(17570): onLoadLanguage() - LANG_COUNTRY_AVAILABLE
  04-22 12:07:16.206: E/Samsung TTS(17570): onLoadLanguage() - lang : eng, country : USA, variant : f01
  04-22 12:07:16.516: E/ViewRootImpl(2399): sendUserActionEvent() mView == null
  04-22 12:07:16.516: E/EnterpriseContainerManager(2399): ContainerPolicy Service is not yet ready!!!
  04-22 12:07:20.421: E/Watchdog(2399): !@Sync 14478
  </code></pre>