Tnroute Error for TNServer 46 Service Pack 1

We recently upgrade our TNServer from 4.5.1 to 4.6 and 4.6SP1. During the old version, our flow services that used tn.route is working fine but when we upgrade to new version with the latest SP1, we got some errors. Below are the error message:

2003-04-21 10:26:13 com.wm.app.tn.err.EXMLException:

wm.tn:log

  com.wm.app.b2b.server.ServiceException 
  No briefMessage specified for event 
  com.wm.app.b2b.server.ServiceException: No briefMessage specified for event 

at wm.tn.log(tn.java:148)
at java.lang.reflect.Method.invoke(Native Method)
at com.wm.app.b2b.server.JavaService.baseInvoke(JavaService.java:281)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:688)
at com.wm.app.b2b.server.BaseService.invoke(BaseService.java:140)
at com.wm.lang.flow.FlowInvoke.invoke(FlowInvoke.java:292)
at com.wm.lang.flow.FlowState.invokeNode(FlowState.java:559)
at com.wm.lang.flow.FlowState.step(FlowState.java:430)
at com.wm.lang.flow.FlowState.invoke(FlowState.java:400)
at com.wm.app.b2b.server.FlowSvcImpl.baseInvoke(FlowSvcImpl.java:1786)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:688)
at com.wm.app.b2b.server.BaseService.invoke(BaseService.java:140)
at com.wm.lang.flow.FlowInvoke.invoke(FlowInvoke.java:292)
at com.wm.lang.flow.FlowState.invokeNode(FlowState.java:559)
at com.wm.lang.flow.FlowState.step(FlowState.java:430)
at com.wm.lang.flow.FlowState.invoke(FlowState.java:400)
at com.wm.app.b2b.server.FlowSvcImpl.baseInvoke(FlowSvcImpl.java:1786)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:688)
at com.wm.app.b2b.server.BaseService.invoke(BaseService.java:140)
at com.wm.lang.flow.FlowInvoke.invoke(FlowInvoke.java:292)
at com.wm.lang.flow.FlowState.invokeNode(FlowState.java:559)
at com.wm.lang.flow.FlowState.step(FlowState.java:430)
at com.wm.lang.flow.FlowState.invoke(FlowState.java:400)
at com.wm.app.b2b.server.FlowSvcImpl.baseInvoke(FlowSvcImpl.java:1786)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:688)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:450)
at com.wm.app.b2b.server.Service.doInvoke(Service.java:495)
at com.wm.app.b2b.server.Service.doInvoke(Service.java:464)
at com.wm.app.tn.route.RoutingActions.invokeWrapper(RoutingActions.java:814)
at wm.tn.route.invokeWrapper(route.java:809)
at java.lang.reflect.Method.invoke(Native Method)
at com.wm.app.b2b.server.JavaService.baseInvoke(JavaService.java:281)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:688)
at com.wm.app.b2b.server.ServiceManager.invoke(ServiceManager.java:450)
at com.wm.app.b2b.server.ServiceThread.run(ServiceThread.java:74)
at com.wm.util.pool.PooledThread.run(C:/NT/Perforce/basis/4.1.0-terra/module/core/source/com/wm/util/pool/PooledThread.java:103)
at java.lang.Thread.run(Thread.java:484)