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Android java.lang.RuntimeException: Unable to instantiate activity ComponentInfo

Posted by: admin June 15, 2020 Leave a comment


Ok guys this doesn’t make sense to me at all and I don’t understand why I am getting this error in my app. I have registered the activity class in the android manifrest xml..

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.mobile.batteryhelper/com.mobile.batteryhelper.Battery}:
java.lang.ClassNotFoundException: Caused by: java.lang.ClassNotFoundException: com.mobile.batteryhelper.Battery in loader dalvik.system.PathClassLoader[/mnt/asec/com.mobile.batteryhelper-1/pkg.apk]

Here is the androidmanifest.xml. Yes the .Battery class extends Activity also.

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".Battery"
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
How to&Answers:

Have you tried to clean your workspace. Goto Project->Clean and select your project. For some reason eclipse doesn’t build my manifest automatically.


You have put 3rd party library in library folder and reference them. Go to Properties/ Java Build Path/ Libraries/ Add External JARs.

Check the Jar files in the Properties/ Java Build Path/ Order and Export


Have you tried to initialise anything in your class before OnCreate gets called?
If you initialise static variables (for example) it can give you this (infuriatingly obtuse) error.


Actually I found my answer to this same issue here:
java.lang.ClassNotFoundException on working app

You don’t provide a name for the Application tag, only the Activity. So if your issue was the same as mine, you should be able to remove the following and things will work:



I had the same problem. It was a pretty confusing error until I found a way out. Go to Properties>Java Build Path>Order and Export and move your android-support-v4.jar to the top. It worked fine for me. Try it out.


Either your manifest package is not com.mobile.batteryhelper, or there is no com.mobile.batteryhelper.Battery class in your code. Possibly you don’t have a public constructor for the class or the class is not declared public (though I think you would get a slightly different error message in that case).

Make sure that you aren’t using ProGuard to strip your code. Make sure the class is public, in the correct package (same as your manifest package), and doesn’t have a constructor. Also it would be useful to see the entire error stack crawl in case there is something useful inside of it.


Right click on your Battery class > BuildPath > Exclude
Right click on your Battery class > BuildPath > Include your class again


I got this problem and fix it by moving all .jar files (external library files) which put in “lib” folder to “libs” folder. Somehow, eclipse only know .jar files put in libs folder


I had the same problem and I solved it by updating the ADT plugin.


See the crash log carefully:

loader dalvik.system.PathClassLoader[/mnt/asec/com.mobile.batteryhelper-1/pkg.apk

Here mnt means external SD card.

Normally, when android:installLocation="auto" is set in
AndroidManifest.xml, if the device won’t have enough phone memory, then the
app will be stored on the SD card. Once you remove the SD card from
the device, the app can’t find the APK location, then the app crashes.

Steps to produce the crash:

Issue able to replicate in HTC sensation 2.3.4 version.

  • Move the app to SD Card by going to
    Settings–>Manage applications->Click on the app–>Move to SD card
  • Remove the SD card from the device and open the app

If you try with a Samsung device, it won’t crash, but it won’t show the app if you remove the SD Card. This behaviour is for a few devices only.


you can just remove the app from your mobile phone or your emulator


What worked for me is deleting the innermost files inside “build” folder, which are the files inside generated, intermediates, outputs, and tmp.