环信集成初始化时报NoClassDefFoundError:

在华为荣耀6.0系统上可以正常运行，在三星4.3的手机上初始化失败：

1.集成时已将将Demo中的 DemoHelper和DemoModel拷入到了自己的项目下面
2.在Application的onCreate()中调用DemoHelper.getInstance().init(this);进行初始化报错如下：

threadid=1: thread exiting with uncaught exception (group=0x422ad700)

12-22 14:29:26.710 6568-6568/? W/System.err: java.lang.NoClassDefFoundError: com.lingfeng.appdemo.functions.chat.DemoModel

12-22 14:29:26.710 6568-6568/? W/System.err:     at com.lingfeng.appdemo.functions.chat.DemoHelper.init(DemoHelper.java:154)

12-22 14:29:26.710 6568-6568/? W/System.err:     at com.lingfeng.appdemo.MyApplication.onCreate(MyApplication.java:48)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1024)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4702)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.app.ActivityThread.access$1400(ActivityThread.java:168)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1389)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:99)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.os.Looper.loop(Looper.java:137)

12-22 14:29:26.710 6568-6568/? W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5493)

12-22 14:29:26.710 6568-6568/? W/System.err:     at java.lang.reflect.Method.invokeNative(Native Method)

12-22 14:29:26.710 6568-6568/? W/System.err:     at java.lang.reflect.Method.invoke(Method.java:525)

12-22 14:29:26.710 6568-6568/? W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209)

12-22 14:29:26.710 6568-6568/? W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025)

12-22 14:29:26.710 6568-6568/? W/System.err:     at dalvik.system.NativeStart.main(Native Method)

哪位大神帮忙看看，谢谢