unfortunately, Crystalball has stopped

Hi, I've got this annoying error that's been keeping me busy for at least two hours. Either my emulator won't run my app at all (1) or it will run but it will show an error in the emulator that says: "unfortunately, Crystallball has stopped" (2)

I find the answers that I found on this forum very vague and hopefully someone is able to help me.

Logcat returns this:

05-30 19:35:02.415: W/dalvikvm(1255): threadid=1: thread exiting with uncaught exception (group=0xb2abeba8) 05-30 19:35:02.445: E/AndroidRuntime(1255): FATAL EXCEPTION: main 05-30 19:35:02.445: E/AndroidRuntime(1255): Process: com.example.crystalball, PID: 1255 05-30 19:35:02.445: E/AndroidRuntime(1255): java.lang.NoClassDefFoundError: android.support.v7.appcompat.R$styleable 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:107) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:58) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:98) 05-30 19:35:02.445: E/AndroidRuntime(1255): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:18) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.Activity.performCreate(Activity.java:5231) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.ActivityThread.access$800(ActivityThread.java:135) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.os.Handler.dispatchMessage(Handler.java:102) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.os.Looper.loop(Looper.java:136) 05-30 19:35:02.445: E/AndroidRuntime(1255): at android.app.ActivityThread.main(ActivityThread.java:5017) 05-30 19:35:02.445: E/AndroidRuntime(1255): at java.lang.reflect.Method.invokeNative(Native Method) 05-30 19:35:02.445: E/AndroidRuntime(1255): at java.lang.reflect.Method.invoke(Method.java:515) 05-30 19:35:02.445: E/AndroidRuntime(1255): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 05-30 19:35:02.445: E/AndroidRuntime(1255): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 05-30 19:35:02.445: E/AndroidRuntime(1255): at dalvik.system.NativeStart.main(Native Method) 05-30 19:40:03.045: I/Process(1255): Sending signal. PID: 1255 SIG: 9

Since Crystalball is the very first project and I have absolutely no idea what this means let alone how to solve it, I'm in very desprate need of your help.

Thanks!!