title: java.lang.RuntimeException: Unable to instantiate activity ComponentInfo
body: <p>I was trying to run a sample code 
  While launching the application in the android 1.5 emulator , I got these errors....
  Any one have some hint..?</p>
  
  <p>ERROR from LogCat:</p>
  
  <pre><code>01-13 02:28:08.392: ERROR/AndroidRuntime(2888): FATAL EXCEPTION: main
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.s.android.test/com.s.android.test.MainActivity}: java.lang.ClassNotFoundException: com.s.android.test.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.s.android.test-2.apk]
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1544)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1638)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:928)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.os.Handler.dispatchMessage(Handler.java:99)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.os.Looper.loop(Looper.java:123)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.ActivityThread.main(ActivityThread.java:3647)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at java.lang.reflect.Method.invokeNative(Native Method)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at java.lang.reflect.Method.invoke(Method.java:507)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at dalvik.system.NativeStart.main(Native Method)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888): Caused by: java.lang.ClassNotFoundException: com.s.android.test.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.s.android.test-2.apk]
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1536)
  01-13 02:28:08.392: ERROR/AndroidRuntime(2888):     ... 11 more
  01-13 02:28:08.407: WARN/ActivityManager(112):   Force finishing activity com.s.android.test/.MainActivity
  </code></pre>
  
  <p><strong>Edit</strong>
  This error happens to most of the beginners, the thing is that you have to add all your activities in the Manifest file.</p>