public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button viewAbout = (Button) findViewById(R.id.buttonAbout);

        // //onClickListeners// //

        viewAbout.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {

                Intent i = new Intent(MainActivity.this, About.class);
                startActivity(i);  //This is line 50
                                   //This is line 51 where the logcat will refer
            }                      // This is line 52
        });
    }
}

02-22 12:44:22.095: E/AndroidRuntime(2743): FATAL EXCEPTION: main
02-22 12:44:22.095: E/AndroidRuntime(2743): Process: biz.midl.debteliminator, PID: 2743
02-22 12:44:22.095: E/AndroidRuntime(2743): android.content.ActivityNotFoundException: Unable to find explicit activity class {biz.midl.debteliminator/biz.midl.debteliminator.About}; have you declared this activity in your AndroidManifest.xml?
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1628)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.Instrumentation.execStartActivity(Instrumentation.java:1424)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.Activity.startActivityForResult(Activity.java:3424)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.Activity.startActivityForResult(Activity.java:3385)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.Activity.startActivity(Activity.java:3627)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.Activity.startActivity(Activity.java:3595)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at biz.midl.debteliminator.MainActivity$1.onClick(MainActivity.java:51)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.view.View.performClick(View.java:4438)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.view.View$PerformClick.run(View.java:18422)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.os.Handler.handleCallback(Handler.java:733)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.os.Handler.dispatchMessage(Handler.java:95)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.os.Looper.loop(Looper.java:136)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at android.app.ActivityThread.main(ActivityThread.java:5017)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at java.lang.reflect.Method.invokeNative(Native Method)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at java.lang.reflect.Method.invoke(Method.java:515)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
02-22 12:44:22.095: E/AndroidRuntime(2743):     at dalvik.system.NativeStart.main(Native Method)

<activity
        android:name="biz.midl.debteliminator.About"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.DeviceDefault.Light.NoActionBar.Fullscreen" >
        <intent-filter>
            <action android:name="android.intent.action.ABOUT" />

        </intent-filter>
    </activity>