Entity Server Exception was Unhandled

I tried to add a form to my project with buttons to execute various queries and write the query results to the console. I noticed that none of the tutorials use forms as yet so I may be venturing into unimlemented territory but nothing ventured, nothing gained. The form code is as follows:

 

Public Class Form1

   Private Shared aManager As DomainModel.Manager = New DomainModel.Manager()

   Public Sub New()

      ' This call is required by the Windows Form Designer.
      InitializeComponent()

      ' Add any initialization after the InitializeComponent() call.

   End Sub

   Private Sub Query01()
      Dim query = aManager.Customers
      For Each aCustomer As DomainModel.Customer In query
         Console.WriteLine(aCustomer.CompanyName)
      Next aCustomer
      'Console.WriteLine()
      ' Console.WriteLine("Press ENTER to close window.")
      'Console.ReadLine()
   End Sub

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
      Query01()
   End Sub
End Class

When I run tha app and click on Button1 I get Server Exception was Unhandled when the For Each statement is executed. The details of the exception is as follows:

 

 

 

IdeaBlade.EntityModel.v4.EntityServerException was unhandled
  Cancelled=False
  Message="Value cannot be null. Parameter name: key"
  Source="IdeaBlade.EntityModel.v4"
  StackTrace:
       at IdeaBlade.EntityModel.v4.EntityManager.HandleEntityServerException(Exception pException, Boolean pTryToHandle, PersistenceOperation pOperation)    at IdeaBlade.EntityModel.v4.EntityManager.ExecuteServerQuery(IEntityQuery pEntityQuery)    at IdeaBlade.EntityModel.v4.EntityManager.ExecuteFetch(IEntityFinder finder)    at IdeaBlade.EntityModel.v4.EntityQueryFinder.Execute()    at IdeaBlade.EntityModel.v4.EntityManager.ExecuteQueryCore(IEntityQuery query, QueryStrategy strategy)    at IdeaBlade.EntityModel.v4.EntityManager.ExecuteQuery[T](IEntityQuery query, QueryStrategy strategy, Boolean checkT)    at IdeaBlade.EntityModel.v4.EntityManager.ExecuteQuery[T](IEntityQuery`1 query)    at IdeaBlade.EntityModel.v4.EntityQuery`1.GetEnumerator()    at DevForceEFTest2.Form1.Query01() in C:\Documents and Settings\Ron\My Documents\Visual Studio 2008\Projects\DevForceTest2\DevForceEFTest2\Form1.vb:line 16    at DevForceEFTest2.Form1.Button1_Click(Object sender, EventArgs e) in C:\Documents and Settings\Ron\My Documents\Visual Studio 2008\Projects\DevForceTest2\DevForceEFTest2\Form1.vb:line 25    at System.Windows.Forms.Control.OnClick(EventArgs e)    at System.Windows.Forms.Button.OnClick(EventArgs e)    at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)    at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)    at System.Windows.Forms.Control.WndProc(Message& m)    at System.Windows.Forms.ButtonBase.WndProc(Message& m)    at System.Windows.Forms.Button.WndProc(Message& m)    at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)    at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)    at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)    at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)    at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)    at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)    at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)    at System.Windows.Forms.Application.Run(ApplicationContext context)    at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()    at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()    at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)    at DevForceEFTest2.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81    at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)    at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)    at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()    at System.Threading.ThreadHelper.ThreadStart_Context(Object state)    at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)    at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.ArgumentNullException
       Message="Value cannot be null. Parameter name: key"
       ParamName="key"
       Source="IdeaBlade.EntityModel.v4"
       StackTrace:
            at IdeaBlade.EntityModel.v4.EntityServerProxy.CheckConnection(Exception pException)    at IdeaBlade.EntityModel.v4.EntityServerProxy.Fetch(SessionBundle pBundle, IEntityQuery pQuery)    at IdeaBlade.EntityModel.v4.EntityManager.ExecuteServerQuery(IEntityQuery pEntityQuery)
       InnerException:

 

Thanks for reporting this, and for your patience.

 

The problem is somewhat related to our improper handling of namespaces in VB, and also to our current expectation that the type names used in the model (the c-space) correspond to the type names in the generated code in the EF assembly (the o-space).  If you clear out the Root namespace in your EF project and then re-build, this should work.

 

We're already fixing the namespace problem.  I'll open two additional problem reports:  one to address the c-space / o-space name restriction, and another to provide better error messages for these kinds of failures (since this particular error message is quite confusing and misleading).

 

 

 

If you'd like, you can zip up your solution and email it to support, attn: Kim, and I'll take a look.