Unhandled exception System.InvalidOperationException: The calling thread cannot access this object because a different thread owns it.
   at System.Windows.Threading.Dispatcher.VerifyAccess()
   at System.Windows.DependencyObject.GetValue(DependencyProperty dp)
   at Telerik.Windows.Data.SortDescriptorBase.get_SortDirection()
   at Telerik.Windows.Data.Expressions.SortDescriptorCollectionExpressionBuilder.Sort()
   at Telerik.Windows.Data.QueryableExtensions.Sort(IQueryable source, IEnumerable`1 sortDescriptors)
   at Telerik.Windows.Data.QueryableExtensions.Sort(IQueryable source, SortDescriptorCollection sortDescriptors)
. . .