O Android Studio não consegue encontrar a classe de atividade explícita

<activity
    android:name="com.example.assignment.androidassignment.MainActivity"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.Holo.Dialog" >

    <intent-filter>
        <action android:name="android.intent.action.MAIN" />    
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>
<activity
     android:name="com.example.assignment.androidassignment.ViewAllEmployee"/>