RuntimeException: Unable to instantiate application

When I run my application, everytime I am getting the below exception in my logcat:

 04-14 09:29:53.965: W/dalvikvm(1020): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
    04-14 09:29:53.985: E/AndroidRuntime(1020): FATAL EXCEPTION: main
    04-14 09:29:53.985: E/AndroidRuntime(1020): java.lang.RuntimeException: Unable to instantiate application   android.app.Application: java.lang.NullPointerException
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.LoadedApk.makeApplication(LoadedApk.java:482)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3938)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.ActivityThread.access$1300(ActivityThread.java:123)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1185)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.os.Handler.dispatchMessage(Handler.java:99)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.os.Looper.loop(Looper.java:137)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.ActivityThread.main(ActivityThread.java:4424)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at java.lang.reflect.Method.invokeNative(Native Method)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at java.lang.reflect.Method.invoke(Method.java:511)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at dalvik.system.NativeStart.main(Native Method)
    04-14 09:29:53.985: E/AndroidRuntime(1020): Caused by: java.lang.NullPointerException
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java:362)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.LoadedApk.getClassLoader(LoadedApk.java:305)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     at android.app.LoadedApk.makeApplication(LoadedApk.java:474)
    04-14 09:29:53.985: E/AndroidRuntime(1020):     ... 11 more

Note: When I uninstall the app from the emulator and run it, then I don't get this exception but when I re-run the installed application in emulator, I am getting this. Please help.

This is a verbose error message raised by underlying framework when dalvik re-install .apk file and trying to reuse or recycle the previous opened activity/view from the same package (if you haven't closed the previous installed app yet). It has nothing to do with your app, moreover, it is very unlikely that your app will get freezed or crashed cause by this verbose error message on end user's device.

It seems that this dalvik verbose error log only happend on Android 4.0 system, I've tested it myself on Android 3.2 and 2.3.3 running environment, where you cannot replicate to get this message shown on neither of them. A similar question has been discussed before at here and someone has filled a bug report in Android Issues Tracker.

I don't think you should concern too much about this verbose error log at the moment, if you look more logs before and after this red error in Logcat, you can see the full story and find that the previous opened activity/view (which are marked as died state) get killed and the newly re-installed one get poped ultimately.

I realise it's a very old question, but this may be useful anyway. I've found that when I observe this error in my own development, it's due to the previously running instance of my app not closing down neatly, for example by shutting down background threads prior to exit.