Getting Exception

问题

I'm getting the following exception when calling 'GetProjectItemSummariesQuery' against my RIA Service. The weird thing is that it only happens once every four or five times I call the function.

System.ServiceModel.DomainServices.Client.DomainOperationException: Load operation failed for query 'GetProjectItemSummaries'. Object reference not set to an instance of an object.
   at System.ServiceModel.DomainServices.Client.OperationBase.Complete(Exception error)
   at System.ServiceModel.DomainServices.Client.LoadOperation.Complete(Exception error)
   at System.ServiceModel.DomainServices.Client.DomainContext.CompleteLoad(IAsyncResult asyncResult)
   at System.ServiceModel.DomainServices.Client.DomainContext.<>c__DisplayClass1b.<Load>b__17(Object )   

Edits:

I placed a try/catch in both the service that is being called and the calling function. They caught nothing.

回答1:

Configure WCF Tracing and try to catch what's really going on.

回答2:

A faulty set SortDescriptor or FilterDescriptor could produce the same error

来源：https://stackoverflow.com/questions/5596510/getting-exception