No service handlers found on operations port

No service handlers found on operations port with field name:_positionPortCategory StdOut
Level Info
Time 2007-09-06T23:53:49.92875-04:00
Subject No service handlers found on operations port with field name:_positionPort
Source http://roboben:50000/playdata
CodeSite Microsoft.Ccr.Core.Interleave CreateInterleaveFromDsspOperationHandlers(Microsoft.Dss.ServiceModel.DsspServiceBase.DsspServiceBase, Microsoft.Ccr.Core.IPortSet, System.String)() at line:0, file

[Contract(Contract.Identifier)]
[AlternateContract(pos2d.Contract.Identifier)]
public class PlayDataService : DsspServiceBase
{
private PlayDataState _state = new PlayDataState();

[ServicePort("/playdata", AllowMultipleInstances=false)]
private PlayDataOperations _mainPort = new PlayDataOperations();

[AlternateServicePort("/position", AllowMultipleInstances = false, AlternateContract = pos2d.Contract.Identifier)]
private pos2d.SimplePositionOperations _positionPort = new pos2d.SimplePositionOperations();

...

protected override void Start()
{
...

//position operations
MainPortInterleave.CombineWith(
new Interleave(
new ExclusiveReceiverGroup(
Arbiter.ReceiveWithIterator<pos2d.Replace>(true, _positionPort, PositionReplaceHandler)
),
new ConcurrentReceiverGroup(
Arbiter.ReceiveWithIterator<pos2d.Get>(true, _positionPort, PositionGetHandler)
)
)
);

}

...

public IEnumerator<ITask> PositionGetHandler(pos2d.Get get)
{
get.ResponsePort.Post(_state.PositionState);
yield break;
}

public IEnumerator<ITask> PositionReplaceHandler(pos2d.Replace replace)
{
_state.PositionState = replace.Body;
replace.ResponsePort.Post(DefaultReplaceResponseType.Instance);
yield break;
}

...
}