Unable to instantiate activity in android

Most times this error has to do with the Manifest.xml file.

My advice is first to check  the Main Activity name if is the same with the Activity you use in your code:
<activity android:name=".MainActivity" />

And then check if your package got the same name as you named it when you create the Project.
You can find "package" property inside :
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="" >


It's a common mistake if you import your project code from another project or you change the main activity name.

Add project to working set - eclipse

right click on the working set you want and then click on Properties.

Select the project and Add it to the Working set content.

Remove Title Bar on Android

Remember when you wrote the first "Hello World" app ?

Hello World or whatever you named it appears in the title bar of Android.

Go to the manifest file. Find the <application> tag and change it to this :


    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar"
         >

we have added the code in bold... it does the work for us. Now just run again your app.