[Project Server 2010] Error get Lookup Table

Hi everyone,

I am a new developer in Project Server 2010. I use PSI (Web service ) to get LookupTable.

It works well on local but It have error when I change server.

My code: 

SvcLookupTable.LookupTableDataSet dts_lookup = lookup.ReadLookupTables("", false, 0);

And Error (Catch Ex):

System.Web.Services.Protocols.SoapException: Unhandled Communication Fault occurred
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at SvcLookupTable.LookupTable.ReadLookupTables(String xmlFilter, Boolean autoCheckOut, Int32 language)

Please help me and show me the reason.

I wish I would see your response soon.

Thanks and Regards,

An Pham