OK, I finally figured out the problem.  Taking a hint after looking up the error "An item with the same key has already been added.", I saw that in the class ItemRec, which I am returning as an object in the list, there were two properties named "Items" both of which had two parameters that differed so basically one property was an overload of the other.  But the report evidently doesn't like two fields under the Data Source to have the same name.  I renamed one of these properties and now I am having no more problems.  I suppose I should have made a special class for this report to be the object returned and might still do that.

Hopefully this may help someone else who runs across this same type of problem.

Thanks again to the Leo for the offer of help.

Kurt

This might be another piece to the puzzle.  I made the function in my ItemRec class to be IEnumerable but changed the one in my ItemDB class which the calling function returns as just a List(of ItemRec) rather than IEnumerable.  I still get the error putting a field from the Object DataSource that I'm pointing to the IEnumerable function in my ItemRec class on the form body.  If I don't try to do anything (move it, look at its properties, etc.) to that field, I don't get the restart dialog error.  But if I go to the preview of the report, I get the following error (I'm not sure what it means):

nfragistics.Controls.Reports.ReportViewerException: An unknown error occurred while processing the report. ---> System.ArgumentException: An item with the same key has already been added.
   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
   at Infragistics.Reports.Expressions.ExternalType.GetProperties()
   at Infragistics.Reports.Expressions.EvaluationContext.AddDataSource(DataSource dataSource)
   at Infragistics.Reports.Expressions.EvaluationContextFactory.AddDataSources(IEvaluationContext context, IEnumerable`1 dataSources)
   at Infragistics.Reports.Expressions.EvaluationContextFactory.GetParseContext(DataParseContext parseContext, ITypeFactory typeFactory, Boolean enableTypeChecking)
   at Infragistics.Designers.Reports.Validation.BindingValidationProvider.Validate(Binding binding, ReportItem item, Report report)
   at Infragistics.Designers.Reports.Validation.BindingValidationProvider.Validate(DataObject model, ValidationManager validationManager)
   at Infragistics.Designers.Reports.ValidationManager.Validate(DataObject model, IValidationCategory validationCategory, HashSet`1 alreadyValidated, Boolean recursive)
   at Infragistics.Designers.Reports.ValidationManager.Validate(DataObject model, IValidationCategory validationCategory, HashSet`1 alreadyValidated, Boolean recursive)
   at Infragistics.Designers.Reports.ValidationManager.Validate(DataObject model, IValidationCategory validationCategory, HashSet`1 alreadyValidated, Boolean recursive)
   at Infragistics.Designers.Reports.ValidationManager.OnTransactionEnded(Object sender, DataTransactionEventArgs e)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at Infragistics.Designers.UndoRedoManager.OnTransactionManagerEnded(Object sender, DataTransactionEventArgs e)
   at Infragistics.Models.Data.Transactions.TransactionManager.NotifyTransactionEnded(DataTransaction transaction)
   at Infragistics.Models.Data.Transactions.DataTransaction.CommitChanges()
   at Infragistics.Models.Data.Transactions.TransactionContext.NotifySetPropertyValue[T](DataObject obj, DataProperty property, T oldValue, T newValue)
   at Infragistics.Models.Data.Transactions.AttachingContext.NotifySetPropertyValue[T](DataObject obj, DataProperty property, T oldValue, T newValue)
   at Infragistics.Models.Data.DataObjectImpl.NotifyValueSet[T](DataObject obj, DataProperty property, T oldValue, T newValue, Action`2 propertyChanged)
   at Infragistics.Models.Data.DataObject.SetValueInternal(DataProperty property, Object value)
   at Infragistics.Models.Data.DataObject.InvokeSetValue(DataProperty property, Object value)
   at Infragistics.Models.Data.DataId.GenerateUuid(DataObject obj, Boolean& newId)
   at Infragistics.Controls.Reports.PreviewRenderingEngineFactory.CalculateReportDefinitionGuids(DataObjectVisitor visitor, DataObject reportDefChildren)
   at Infragistics.Models.Data.Visitors.DataObjectVisitor.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.VisitorWriter.WriteDataObject(DataProperty property, DataObject obj)
   at Infragistics.Reports.DataSource.WriteValues(IDataPropertyWriter writer)
   at Infragistics.Reports.ObjectDataSource.WriteValues(IDataPropertyWriter writer)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitor.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.VisitDataCollection(DataProperty property, IDataCollection collection)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitor.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.VisitorWriter.WriteDataObject(DataProperty property, DataObject obj)
   at Infragistics.Reports.Report.WriteValues(IDataPropertyWriter writer)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitor.VisitDataObject(DataProperty property, DataObject obj)
   at Infragistics.Models.Data.Visitors.DataObjectVisitorBase.Visit(DataObject obj)
   at Infragistics.Controls.Reports.PreviewRenderingEngineFactory.GenerateReportDefinitionGuids(Report reportDefinition)
   at Infragistics.Controls.Reports.PreviewRenderingEngineFactory.CreateLocalEngine(ReportSource reportSource, Assembly reportAssembly, IEnumerable`1 dataSources)
   at Infragistics.Controls.Reports.ProcessingSessionStateMachine.CreateProcessor(IRenderingEngineFactory renderingEngineFactory, IEnumerable`1 externalDataSources, Report reportDefinition, Assembly reportAssembly)
   --- End of inner exception stack trace ---
   at Infragistics.Controls.Reports.ProcessingSessionStateMachine.CreateProcessor(IRenderingEngineFactory renderingEngineFactory, IEnumerable`1 externalDataSources, Report reportDefinition, Assembly reportAssembly)
   at Infragistics.Controls.Reports.ViewerStateMachine.RenderHelper(RenderParameters renderParameters, Report reportDefinition, Assembly reportAssembly)

Thanks for any help.

Kurt

Thanks, Leo.

I don't think I can take the time to scale down the solution I'm trying to put this report into.  I have verified that the problem stems from the Object DataSource (which I'm sure I want to use since I want to fill the solution from a stored procedure and can't figure out how to do that using a SQL DataSource) as I was able to define a test SQL Data Source and put fields from it on the report form just fine.  I'm not at all familiar with using the IEnumerable interface and that is probably the source of my problem.

Here are snippets (very scaled down and genericized for purposes of putting into a public forum) of the code I used to set up the object which I used as the Object DataSource which points to the GetItem function of the ItemRec class:

ItemRec class

    Public Shared Function GetItem(ByVal intItemID As Integer) As IEnumerable(Of ItemRec)
        Return ItemDB.GetItemForReport(intItemID)
    End Function

ItemDB class

    Public Shared Function GetItemForReport(ByVal intItemID As Integer) As IEnumerable(Of ItemRec)
        Dim itm As New ItemRec

        Dim con As SqlConnection = Connection.GetConnection
        Dim cmd As New SqlCommand("spGetRptItem", con)
        cmd.CommandType = CommandType.StoredProcedure
        cmd.Parameters.AddWithValue("@item_id", intItemID)
        Dim rdr As SqlDataReader
        con.Open()
        rdr = cmd.ExecuteReader
        If rdr.Read Then
            With itm
                .ItemDate = rdr.Item("fldItemDate")
                .ItemNumber = rdr.Item("fldItemNumber")
                .Description = rdr.Item("fldDescription")
                .Quantity = rdr.Item("fldQuantity")
            End With
        End If
        rdr.Close()
        con.Close()
        Dim items As New List(Of ItemRec)
        items.Add(itm)
        Return items
    End Function

I appreciate any help getting this code functional as it must not be at the moment.  But I'm wondering why it caused a fatal error in the Design environment and not some friendlier error.

That makes sense that the installer did install the latest version of the Reporting DLL.

Thanks for your help,

Kurt