Workaround:

private IList<PivotGroupNode> collapsedRowsNodes;
private void customMenuItem_Click(object sender, EventArgs e)
{
    PivotGridSpreadExport spreadExport = new PivotGridSpreadExport(pivotGrid);
    spreadExport.ExportCompleted += spreadExport_ExportCompleted;
    spreadExport.ExportFlatData = true;

    this.collapsedRowsNodes = new List<PivotGroupNode>();
    PivotGridGroupTraverser rowTraverser = (PivotGridGroupTraverser)this.pivotGrid.PivotGridElement.RowScroller.Traverser.GetEnumerator();
    while (rowTraverser.MoveNext())
    {
        PivotGroupNode current = rowTraverser.Current;
        if (!current.Expanded)
        {
            this.collapsedRowsNodes.Add(current);
            current.Expanded = true;
        }
    }

    spreadExport.RunExport(@"..\..\export.xlsx", new SpreadExportRenderer());
}

private void spreadExport_ExportCompleted(object sender, EventArgs e)
{
    foreach (PivotGroupNode node in this.collapsedRowsNodes)
    {
        node.Expanded = false;
    }
}

You save 2 config, one with Report filter (1), one without (2), if you load first (1), if puts report filter correctly, but if you load then (2) - report filter still as on (1).
Also, if you load config with ShowFilterArea=true - it  stays visible if you load another config with ShowFilterArea=true 

Hello Alex,

While investigating the reported behavior I managed to isolate an issue in the Save/Load API of RadPivotGrid regarding the ShowFilterArea property. The default value of this property is not serialized, however this can be altered by adding a serialization meta data to the XmlSerializationInfo instance of the pivot. In this scenario the engine did not respect the added new data. Here is the feedback item and you can subscribe to it: http://feedback.telerik.com/Project/154/Feedback/Details/196273-fix-radpivotgrid-the-saveloadlayout-string-overload-does-not-use-the-radpivotg. The item is already in development and a permanent fix will be available with our next release.

Regarding the empty filter descriptions, in order to serialize them one should work with a DataProviderSerializer class. Currently our engine does not save the empty filters and we will consider modifying it so that even if the collection is empty it also be serialized.

I am attaching to this post a sample project with which you would be able to achieve both of your tasks. Please note that the serialization API of the LocalDataSourceProvider uses the DataContract and you would need to use our .NET 4.0 assemblies.

I hope this helps. In case you need additional assistance please write here or open a support ticket.

Regards, 
Hristo

How to reproduce check the attached project and video

Workaround: handle the UpdateCompleted event and explicitly set the properties to true

public LocalDataSourceSerializerForm()
{
    InitializeComponent();

    this.radPivotGrid1.AutoExpandColumnHeaders = false;
    this.radPivotGrid1.AutoExpandRowHeaders = false;

    this.radPivotGrid1.UpdateCompleted += radPivotGrid1_UpdateCompleted;
}

private void radPivotGrid1_UpdateCompleted(object sender, EventArgs e)
{
    this.radPivotGrid1.AutoExpandColumnHeaders = true;
    this.radPivotGrid1.AutoExpandRowHeaders = true;
}

Until the feature gets implemented use custom PivotGridPrintStyle:

Public Class MyPivotGridPrintStyle
    Inherits PivotGridPrintStyle

    Const MIN_SPACE As Integer = 1

    Public Overrides Sub DrawPage(drawArea As Rectangle, graphics As Graphics, pageNumber As Integer)

        If Me.PivotGrid.ColumnHeaderHeight > MIN_SPACE Then
            MyBase.DrawPage(drawArea, graphics, pageNumber)

        Else
            Dim x As Integer = drawArea.X
            Dim y As Integer = drawArea.Y
            Dim scale As SizeF = DirectCast(Me.GetType().BaseType.GetMethod("GetScaleFactors", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me, New Object() {drawArea}), SizeF)

            Dim startColumn As Integer = DirectCast(Me.GetType().BaseType.GetMethod("GetStartColumn", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me, New Object() {pageNumber, drawArea, scale.Width}), Integer)
            Dim endColumn As Integer = DirectCast(Me.GetType().BaseType.GetMethod("GetEndColumn", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me, New Object() {startColumn, drawArea, scale.Width}), Integer)
            Dim startRow As Integer = DirectCast(Me.GetType().BaseType.GetMethod("GetStartRow", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me, New Object() {pageNumber, drawArea, scale.Height}), Integer)
            Dim endRow As Integer = DirectCast(Me.GetType().BaseType.GetMethod("GetEndRow", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me, New Object() {startRow, drawArea, scale.Height}), Integer)

            If Me.PivotGrid.ColumnHeaderHeight <= MIN_SPACE Then
                startRow += 1
            End If

            For i As Integer = startRow To endRow
                x = drawArea.X
                Dim maxHeight As Integer = 0

                For j As Integer = startColumn To endColumn
                    Dim columnWidths = DirectCast(Me.GetType().BaseType.GetField("columnWidths", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me), List(Of Integer))
                    Dim rowHeights = DirectCast(Me.GetType().BaseType.GetField("rowHeights", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me), List(Of Integer))

                    Dim elementRect As New Rectangle(x, y, columnWidths(j), rowHeights(i))
                    Dim printElement As RadPrintElement = Me.GetPrintElementForCell(i, j)
                    printElement.ScaleTransform = scale
                    Dim transformedRect As RectangleF = printElement.GetTransformedBounds(elementRect)

                    Me.PrintElement(printElement, drawArea, elementRect, graphics)
                    x += CInt(Math.Floor(transformedRect.Width))
                    maxHeight = Math.Max(maxHeight, CInt(Math.Floor(transformedRect.Height)))
                Next

                y += maxHeight
            Next
        End If
    End Sub

End Class

Workaround:
private void PrintPivotGrid()
{
    MyPivotGridPrintStyle style = new MyPivotGridPrintStyle();
    style.LayoutType = PivotLayout.Tabular;
    this.radPivotGrid1.PrintStyle = style;
    this.radPivotGrid1.PrintPreview();
}

public class MyPivotGridPrintStyle : PivotGridPrintStyle
{
    public override void Initialize()
    {
        base.Initialize();

        FieldInfo fiColumnWidths = this.GetType().BaseType.GetField("columnWidths", BindingFlags.Instance | BindingFlags.NonPublic);
        List<int> columnWidths = (List<int>)fiColumnWidths.GetValue(this);
        RadPivotGridElement pivotGrid = (RadPivotGridElement)this.GetType().BaseType.GetField("pivotGrid", BindingFlags.Instance | BindingFlags.NonPublic)
                                                                                    .GetValue(this);

        for (int i = 0; i < pivotGrid.RowDescriptorsArea.Children.Count; i++)
        {
            RadElement descriptor = pivotGrid.RowDescriptorsArea.Children[i];
            columnWidths[i] = descriptor.Size.Width;
        }
    }
}

How to reproduce:
   var data = this.dbContext.Orders.Where(o => o.OrderID > 10500).Select(o => new
            {
                Id = o.OrderID,
                OrderDate = o.OrderDate,
                ShipDate = o.ShippedDate,
                Freight = o.Freight
            }).ToArray();

this.localDataProvider = new LocalDataSourceProvider() {ItemsSource = data};

Workaround:
1. Instead of  ToArray call ToList
var data = this.dbContext.Orders.Where(o => o.OrderID > 10500).Select(o => new
{
    Id = o.OrderID,
    OrderDate = o.OrderDate,
    ShipDate = o.ShippedDate,
    Freight = o.Freight
}).ToList();

this.localDataProvider = new LocalDataSourceProvider() {ItemsSource = data};

2. Call the ToArray method but do not create anonymous objects.
var data = this.dbContext.Orders.Where(o => o.OrderID > 10500).Select(o => new PivotModel
{
    Id = o.OrderID,
    OrderDate = o.OrderDate,
    ShipDate = o.ShippedDate,
    Freight = o.Freight
}).ToArray();

this.localDataProvider = new LocalDataSourceProvider() {ItemsSource = data};

public class PivotModel
{
    public int Id { get; set; }

    public DateTime? OrderDate { get; set; }

    public DateTime? ShipDate { get; set; }

    public decimal? Freight { get; set; }
}

How to reproduce: check the attached video

Workaround: 
private void button1_Click(object sender, EventArgs e)
{
    this.radPivotFieldList1.DragDropService.PreviewDragDrop += DragDropService_PreviewDragDrop;
}

IGroupDescription cache;
string group;
private void DragDropService_PreviewDragDrop(object sender, Telerik.WinControls.RadDropEventArgs e)
{
    TreeNodeElement nodeElement = e.DragInstance as TreeNodeElement;
    if (nodeElement != null)
    {
        IField field = nodeElement.Data.DataBoundItem as IField;
        string draggedItem = field.FieldInfo.Name;
        IGroupDescription rowDesc = this.radPivotGrid1.RowGroupDescriptions.Where(i => i.GetUniqueName() == draggedItem).FirstOrDefault();
        if (rowDesc != null)
        {
            cache = (IGroupDescription)rowDesc.Clone();
            group = "Row";
        }

        IGroupDescription colDesc = this.radPivotGrid1.ColumnGroupDescriptions.Where(i => i.GetUniqueName() == draggedItem).FirstOrDefault();
        if (colDesc != null)
        {
            cache = (IGroupDescription)colDesc.Clone();
            group = "Column";
        }

        if (cache != null)
        {
            this.radPivotGrid1.UpdateCompleted += radPivotGrid1_UpdateCompleted;    
        }
    }
}

private void radPivotGrid1_UpdateCompleted(object sender, EventArgs e)
{
    this.radPivotGrid1.UpdateCompleted -= radPivotGrid1_UpdateCompleted;
    switch (group)
    {
        case "Row":
            this.radPivotGrid1.RowGroupDescriptions.Add(cache);
            break;
        case "Column":
            this.radPivotGrid1.ColumnGroupDescriptions.Add(cache);
            break;
        default:
            break;
    }

    cache = null;
}

Workaround:
public Form1()
{
    InitializeComponent();

    this.radPivotGrid1.GroupDescriptorElementCreating += radPivotGrid1_GroupDescriptorElementCreating;
}

private void radPivotGrid1_GroupDescriptorElementCreating(object sender, Telerik.WinControls.UI.GroupDescriptorElementCreatingEventArgs e)
{
    FieldInfo fi = e.GroupDescriptorElement.GetType().GetField("filterPopup", BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
    fi.SetValue(e.GroupDescriptorElement, new MyPivotGroupFilterPopup(e.GroupDescriptorElement) { Visible = false });

    e.GroupDescriptorElement.SortDirectionArrow.Visibility = ElementVisibility.Collapsed;
}

public class MyPivotGroupFilterPopup : PivotGroupFilterPopup
    {
        public MyPivotGroupFilterPopup(PivotGroupDescriptorElement pivotGroupDescriptorElement)
            : base(pivotGroupDescriptorElement)
        { }

        protected override void LoadSettings()
        {
            base.LoadSettings();

            this.Items.Remove(SortAZMenuItem);
            this.Items.Remove(SortZAMenuItem);
            this.Items.Remove(SortOptionsMenuItem);
        }
    }

The new API would allow some of the default functions to be removed and custom aggregate functions to be added. At the moment the dialog can be modified like this:

Public Class MyAggregateOptionsDialog
    Inherits AggregateOptionsDialog

    Private availableAggregateFunctions As IList(Of AggregateFunction) = New List(Of AggregateFunction)() From {
        AggregateFunctions.Sum,
        AggregateFunctions.Count,
        AggregateFunctions.Average,
        AggregateFunctions.Max,
        AggregateFunctions.Min,
        AggregateFunctions.Product,
        AggregateFunctions.StdDev,
        AggregateFunctions.StdDevP,
        AggregateFunctions.Var,
        AggregateFunctions.VarP,
        New SqrtSumAggregateFunction()
    }

    Public Overrides Sub LoadSettings(aggregateDescription As PropertyAggregateDescriptionBase)
        MyBase.LoadSettings(aggregateDescription)

        Dim listAggregateFunctions = DirectCast(Me.GetType().BaseType.GetField("listAggregateFunctions", BindingFlags.NonPublic Or BindingFlags.Instance).GetValue(Me), RadListControl)
        listAggregateFunctions.DataSource = availableAggregateFunctions
    End Sub
End Class

How to reproduce: check the attached project and select an item from the drop-down list

The issue may manifest if aggregate descriptions are added on the pivot`s column axis and if their member does not return data.

Check the attached screenshot:

When the RadCheckBox (Defer Layout Mode) triggers the Update command which is no need. This should happen only when the RadCheckBox is unchecked.

What I would like is to be able to export to a named sheet and keep the other sheets in file. For example:
"Sheet 1" (with new values), "Sheet2" (with old values)

Using your current naming convention, the Option might be named FileExportMode.CreateOrOverrideSheet

In this case, other sheets have references to the one in which the RadPivotGrid is exported. Currently, the logic will remove and recreated the sheet which will break the references and lead to an exception.

When a class implements ICustomTypeDescriptor or has a custom TypeDescriptor, the "Field chooser" in the RadPivotGrid displays the correct property display name, but the RadPivotFieldList does not.

User is not able to open the Filter Popup Dialog when filter items contains DBNULL Workaround: Replace the DBNULL values with empty strings in your datatable.

This is mainly focus on DateTime fields. They automatically create children name Day, Week and etc.They should be named “<parentName>.Day”

Only for local field description 

Add in LocalDataSourceFieldDescriptionsProvider property named FormatDisplayNameAsName which turn on/off this functionality 

((LocalDataSourceFieldDescriptionsProvider)((LocalDataSourceProvider)this.radPivotGrid1.DataProvider).FieldDescriptionsProvider).FormatDisplayNameAsFieldName= true