DataPortal.Fetch failed (Invalid operation - fetch not allowed)

I have created Dal, DalMock, Library,Library.Sl, Library.WinRt, DalEF, WcfAppServer projects using CSLA. I have also developed WinRTUI & SilverlightUI projects. In WinRTUI project,I wrote the following code in the MainPage.xaml.cs.

public

sealedpartialclassMainPage : Page

public MainPage()

{

this.InitializeComponent();

GetList();

}

privateasyncvoid GetList()

{

this.grid1.ItemsSource = awaitCompanyList.GetCompanyListAsync();

}

protectedoverridevoid OnNavigatedTo(NavigationEventArgs e)

{

}

}

But I am getting an error as DataPortal.Fetch failed (Invalid operation - fetch not allowed) in GetList().

Any suggestions?