Null pointer exception if i try to run the sample apk

Hi there, I try to build the samples from cocos2d-x-3.0.beta2 but if I start the apk in the emulator i got some exceptions.

My Environment:
Ubuntu 12.04
NDK 8e (tried the 9c with the same problems)
newest ADT with SDK and Eclipse

I build with “python android-build.py hellocpp” and it seems to work. The only warning I got is: APP_PLATFORM android-14 is larger than android:minSdkVersion 9 in ./AndroidManifest.xml

Then I import the Project in Eclipse, run it and got this exception:

Has somebody an idea what the problem is?

02-26 10:21:35.561: D/AndroidRuntime(923): Shutting down VM
02-26 10:21:35.561: W/dalvikvm(923): threadid=1: thread exiting with uncaught exception (group=0xb1b16b90)
02-26 10:21:35.591: E/AndroidRuntime(923): FATAL EXCEPTION: main
02-26 10:21:35.591: E/AndroidRuntime(923): Process: org.cocos2dx.hellocpp, PID: 923
02-26 10:21:35.591: E/AndroidRuntime(923): java.lang.RuntimeException: Unable to start activity ComponentInfo{org.cocos2dx.hellocpp/org.cocos2dx.hellocpp.Cocos2dxActivity}: java.lang.NullPointerException
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ActivityThread.access$700(ActivityThread.java:135)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.os.Handler.dispatchMessage(Handler.java:102)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.os.Looper.loop(Looper.java:137)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ActivityThread.main(ActivityThread.java:4998)
02-26 10:21:35.591: E/AndroidRuntime(923): at java.lang.reflect.Method.invokeNative(Native Method)
02-26 10:21:35.591: E/AndroidRuntime(923): at java.lang.reflect.Method.invoke(Method.java:515)
02-26 10:21:35.591: E/AndroidRuntime(923): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
02-26 10:21:35.591: E/AndroidRuntime(923): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
02-26 10:21:35.591: E/AndroidRuntime(923): at dalvik.system.NativeStart.main(Native Method)
02-26 10:21:35.591: E/AndroidRuntime(923): Caused by: java.lang.NullPointerException
02-26 10:21:35.591: E/AndroidRuntime(923): at android.os.Parcel.readException(Parcel.java:1467)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.os.Parcel.readException(Parcel.java:1415)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.os.storage.IMountService$Stub$Proxy.mkdirs(IMountService.java:750)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ContextImpl.ensureDirsExistOrFilter(ContextImpl.java:2160)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ContextImpl.getObbDirs(ContextImpl.java:874)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ContextImpl.getObbDir(ContextImpl.java:863)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.content.ContextWrapper.getObbDir(ContextWrapper.java:220)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.NativeActivity.onCreate(NativeActivity.java:177)
02-26 10:21:35.591: E/AndroidRuntime(923): at org.cocos2dx.hellocpp.Cocos2dxActivity.onCreate(Cocos2dxActivity.java:11)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.Activity.performCreate(Activity.java:5243)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
02-26 10:21:35.591: E/AndroidRuntime(923): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
02-26 10:21:35.591: E/AndroidRuntime(923): … 11 more

I have this problem too. why? and how to solve it ?help!!!