Error executing call: Service: null Method: play Num Params: 30: speaker_12169629228381: -20002: -1000

hi,everyone:
i installed red5 server (svn standalone) in linux,when i using,red5phone error:

the red5 server getted from svn.

i had modified SipUser.java
__ /appPath = appPath.substring(0, (appPath.length() - 8));/__

[INFO] [pool-4-thread-16] org.red5.server.stream.ProviderService - getVODProviderFile scope path: name: speaker_1216962922838
[WARN] [pool-4-thread-16] org.red5.server.stream.ProviderService - File was null or did not exist: speaker_1216962922838
[INFO] [pool-4-thread-16] org.red5.server.stream.ProviderService - getVODProviderFile scope path: name: speaker_1216962922838
[WARN] [pool-4-thread-16] org.red5.server.stream.ProviderService - File was null or did not exist: speaker_1216962922838
[ERROR] [pool-4-thread-16] org.red5.server.service.ServiceInvoker - Error executing call: Service: null Method: play Num Params: 30: speaker_12169629228381: -20002: -1000
[ERROR] [pool-4-thread-16] org.red5.server.service.ServiceInvoker - Service invocation error
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.ja va:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.red5.server.service.ServiceInvoker.invoke(ServiceInvoker.java:201)
at org.red5.server.net.rtmp.RTMPHandler.invokeCall(RTMPHandler.java:179)
at org.red5.server.net.rtmp.RTMPHandler.onInvoke(RTMPHandler.java:389)
at org.red5.server.net.rtmp.BaseRTMPHandler.messageReceived(BaseRTMPHandler.java:1 43)
at org.red5.server.net.rtmp.RTMPMinaIoHandler.messageReceived(RTMPMinaIoHandler.ja va:126)
at org.apache.mina.common.support.AbstractIoFilterChain$TailFilter.messageReceived (AbstractIoFilterChain.java:570)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(Ab stractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilt erChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceive d(AbstractIoFilterChain.java:648)
at org.apache.mina.filter.executor.ExecutorFilter.processEvent(ExecutorFilter.java :220)
at org.apache.mina.filter.executor.ExecutorFilter$ProcessEventsRunnable.run(Execut orFilter.java:264)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java: 886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at org.red5.server.stream.PlayEngine.play(PlayEngine.java:401)
at org.red5.server.stream.PlayEngine.play(PlayEngine.java:276)
at org.red5.server.stream.PlaylistSubscriberStream.play(PlaylistSubscriberStream.j ava:247)
at org.red5.server.stream.StreamService.play(StreamService.java:297)
at org.red5.server.stream.StreamService.play(StreamService.java:309)
… 18 common frames omitted

pls help me,i want to learn the red5phone project,help.

thank you very much!