Can't save workflow AX 2012.

Hi All,

I got problem when saving Ax 2012 workflow, I catch these errors:

Message (05:33:30 pm)
Caught 'Exception::CLRError'.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ServiceModel.FaultException`1[Microsoft.Dynamics.AX.Framework.Workflow.Model.AxWorkflowServiceReference.AifFault]: Number selection is canceled.

Server stack trace:
   at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.Dynamics.AX.Framework.Workflow.Model.AxWorkflowServiceReference.SysWorkflowConfigurationService.save(SysWorkflowConfigurationServiceSaveRequest request)
   at Microsoft.Dynamics.AX.Framework.Workflow.Model.AxServiceClient.save(String serializedWorkflowConfiguration, Boolean _newConfig, Boolean _newVersion, WorkflowConfigurationVersionType _versionType)
   at Microsoft.Dynamics.AX.Framework.Workflow.Model.WorkflowModel.Save()
   at Microsoft.Dynamics.AX.Framework.Workflow.Model.Design.ModelEditor.SaveAndClose()
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.Dynamics.AX.ManagedInterop.ClrBridgeImpl.InvokeClrInstanceMethod(ClrBridgeImpl* , ObjectWrapper* objectWrapper, Char* pszMethodName, Int32 argsLength, ObjectWrapper** arguments, Boolean* argsAreByRef, Boolean* isException)
Exception has been thrown by the target of an invocation.
Number selection is canceled.

Do you have any ideal on these one?

Many Thanks,

Kind Regards,

Phuong