java.lang.RuntimeException: Unable to instantiate activity ComponentInfo/ ClassNotFoundException

Question

I\'m develop android application and than i wanna additional new Activity i had error on my logcat

My LogCat:

04-19 12:59:17.654: D/AndroidRuntime(18         


        

Answer 1

This can happen if your activity class is inside a default package. I fixed it by moving the activity class to a new package. and changing the manifest.xml

before

activity android:name=".MainActivity"

after

activity android:name="new_package.MainActivity"

Answer 2

I had the same problem, but I had my activity declared in the Manifest file, with the correct name.

My problem was that I didn't have to imported a third party libraries in a "libs" folder, and I needed reference them in my proyect (Right-click, properties, Java Build Path, Libraries, Add Jar...).

About how do you declare an activity in the manifest file, is correct use .ActivityName always that activity be in the main package.

Answer 3

change your activity declaration in the manifest file into

 <activity android:name=".UnlockActivity">

or else

<activity android:name="Yourcompletepackagename.UnlockActivity">

and try

Answer 4

change line from

<activity android:name=".activities.UnlockActivity">  

to

<activity android:name=".com.bvblogic.android.batterypower.activities.UnlockActivity
 ">