Understandable error java.lang.RuntimeException: Unable to instantiate activity ComponentInfo & Didn't find class

Question

To fix the errors mentioned: - Import the app support libraries as projects from sdk/extras/android/support/v7

Now I have this error:

12-04 05:54:16.067: E/AndroidRuntime(1749): FATAL EXCEPTION: main
12-04 05:54:16.067: E/AndroidRuntime(1749): Process: com.tfg.webquest, PID: 1749
12-04 05:54:16.067: E/AndroidRuntime(1749): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.tfg.webquest/com.tfg.webquest.SplashScreenActivity}: java.lang.ClassNotFoundException: Didn't find class "com.tfg.webquest.SplashScreenActivity" on path: DexPathList[[zip file "/data/app/com.tfg.webquest-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.tfg.webquest-1, /system/lib]]
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.os.Handler.dispatchMessage(Handler.java:102)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.os.Looper.loop(Looper.java:136)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.ActivityThread.main(ActivityThread.java:5017)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at java.lang.reflect.Method.invokeNative(Native Method)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at java.lang.reflect.Method.invoke(Method.java:515)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at dalvik.system.NativeStart.main(Native Method)
12-04 05:54:16.067: E/AndroidRuntime(1749): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.tfg.webquest.SplashScreenActivity" on path: DexPathList[[zip file "/data/app/com.tfg.webquest-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.tfg.webquest-1, /system/lib]]
12-04 05:54:16.067: E/AndroidRuntime(1749):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
12-04 05:54:16.067: E/AndroidRuntime(1749):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2112)
12-04 05:54:16.067: E/AndroidRuntime(1749):     ... 11 more

I have solve the java.lang.NoSuchFieldError that I had at the beginning.

Can be useful this information to solve the error:(thank you)

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.tfg.webquest"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="13"
    android:targetSdkVersion="21" />

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".SplashScreenActivity"
        android:label="@string/title_activity_splash_screen" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
    </activity>
    <activity
        android:name=".HomeActivity"
        android:label="@string/title_activity_home" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="com.tfg.webquest.MainActivity" />
    </activity>

    <activity
        android:name=".RegisterActivity"
        android:label="@string/title_activity_register" >
    </activity>
    <activity
        android:name=".RegisterCourseActivity"
        android:label="@string/title_activity_register_course" >
    </activity>
    <activity
        android:name=".RegisterSubjectActivity"
        android:label="@string/title_activity_register_subject" >
    </activity>
    <activity
        android:name=".RegisterSubjectsActivity"
        android:label="@string/title_activity_list_view_checkboxes" >
    </activity>
    <activity
        android:name=".QuestIntroActivity"
        android:label="@string/title_quest_intro_activity" >
    </activity>
    <activity
        android:name=".QuestActivity"
        android:label="@string/title_quest_activity" >
    </activity>
    <activity
        android:name=".StatisticActivity"
        android:label="@string/StatisticActivity" >
    </activity>
    <activity
        android:name=".GameFinishedActivity"
        android:label="@string/GameFinishedActivity" >
    </activity>
    <activity
        android:name=".SettingsActivity"
        android:label="@string/title_activity_settings" >
    </activity>
</application>

</manifest>

Answer 1

I think we can sum up comments discussion in an answer as it's obvious now. You're not adding android support library v7 correctly to your project. You have to add it as an Android library (with resources) not only the jar to libs folder. Follow support v7 .