Eu tenho o download quickbloxquickblox-chat onde segui todas essas regras com o quickblox-chat No login fechado com erros de exceção

Agora eu tenho log de exceção aqui

java.lang.NoClassDefFoundError: com.quickblox.chat.QBChatService
at com.quickblox.sample.chat.ui.activities.SplashActivity.onCreate(SplashActivity.java:41)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.Activity.performCreate(Activity.java:5104)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.os.Handler.dispatchMessage(Handler.java:99)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.os.Looper.loop(Looper.java:137)
02-25 11:11:55.251: E/AndroidRuntime(897):  at android.app.ActivityThread.main(ActivityThread.java:5041)
02-25 11:11:55.251: E/AndroidRuntime(897):  at java.lang.reflect.Method.invokeNative(Native Method)
02-25 11:11:55.251: E/AndroidRuntime(897):  at java.lang.reflect.Method.invoke(Method.java:511)
02-25 11:11:55.251: E/AndroidRuntime(897):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
02-25 11:11:55.251: E/AndroidRuntime(897):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
02-25 11:11:55.251: E/AndroidRuntime(897):  at dalvik.system.NativeStart.main(Native Method)
02-25 11:11:58.441: I/Process(897): Sending signal. PID: 897 SIG: 9

Alguma solução, por favor?