Android App crash during Appstart

Hey I got a problem with my Forms-App. My IOS and WF Apps are running perfectly.
But I am not able to get my Android version running.
This is what I get in Debug-Log:

06-23 14:30:19.352 I/MonoDroid( 1588): UNHANDLED EXCEPTION:
06-23 14:30:19.401 I/MonoDroid( 1588): Java.Lang.RuntimeException: Exception of type 'Java.Lang.RuntimeException' was thrown.
06-23 14:30:19.401 I/MonoDroid( 1588): at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <IL 0x00011, 0x00078>
06-23 14:30:19.411 I/MonoDroid( 1588): at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>m__0 (object) <IL 0x00006, 0x0006b>
06-23 14:30:19.411 I/MonoDroid( 1588): at Android.App.SyncContext/<Post>c__AnonStorey0.<>m__0 () <IL 0x0000c, 0x0005b>
06-23 14:30:19.411 I/MonoDroid( 1588): at Java.Lang.Thread/RunnableImplementor.Run () <IL 0x00011, 0x00097>
06-23 14:30:19.411 I/MonoDroid( 1588): at Java.Lang.IRunnableInvoker.n_Run (intptr,intptr) <IL 0x0000a, 0x000a3>
06-23 14:30:19.411 I/MonoDroid( 1588): at (wrapper dynamic-method) object.2e56ecd8-d83e-4b1d-8214-be9490a098ef (intptr,intptr) <IL 0x00011, 0x0003b>
06-23 14:30:19.421 I/MonoDroid( 1588):   --- End of managed exception stack trace ---
06-23 14:30:19.421 I/MonoDroid( 1588): android.content.res.Resources$NotFoundException: Resource ID #0x0
06-23 14:30:19.421 I/MonoDroid( 1588):  at android.content.res.Resources.getValue(Resources.java:1013)
06-23 14:30:19.421 I/MonoDroid( 1588):  at android.content.res.Resources.getDrawable(Resources.java:658)
06-23 14:30:19.421 I/MonoDroid( 1588):  at md52b5c5a837cc731a471932d40ebcf8aaf.MainActivity.n_onCreate(Native Method)
06-23 14:30:19.431 I/MonoDroid( 1588):  at md52b5c5a837cc731a471932d40ebcf8aaf.MainActivity.onCreate(MainActivity.java:28)
06-23 14:30:19.431 I/MonoDroid( 1588):  at android.app.Activity.performCreate(Activity.java:5008)
06-23 14:30:19.431 I/MonoDroid( 1588):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
06-23 14:30:19.431 I/MonoDroid( 1588):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
06-23 14:30:19.441 I/MonoDroid( 1588):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
06-23 14:30:19.441 I/MonoDroid( 1588):  at android.app.ActivityThread.access$600(ActivityThread.java:130)
06-23 14:30:19.441 I/MonoDroid( 1588):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
06-23 14:30:19.441 I/MonoDroid( 1588):  at android.os.Handler.dispatchMessage(Handler.java:99)
06-23 14:30:19.441 I/MonoDroid( 1588):  at android.os.Looper.loop(Looper.java:137)
06-23 14:30:19.441 I/MonoDroid( 1588):  at android.app.ActivityThread.main(ActivityThread.java:4745)
06-23 14:30:19.451 I/MonoDroid( 1588):  at java.lang.reflect.Method.invokeNative(Native Method)
06-23 14:30:19.451 I/MonoDroid( 1588):  at java.lang.reflect.Method.invoke(Method.java:511)
06-23 14:30:19.451 I/MonoDroid( 1588):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
06-23 14:30:19.451 I/MonoDroid( 1588):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
06-23 14:30:19.451 I/MonoDroid( 1588):  at dalvik.system.NativeStart.main(Native Method)
06-23 14:30:19.481 D/AndroidRuntime( 1588): Shutting down VM
06-23 14:30:19.481 W/dalvikvm( 1588): threadid=1: thread exiting with uncaught exception (group=0x40a122a0)
An unhandled exception occured.