To reproduce:
- Bind the control and set the auto filter functionality.
- Type a value and press the tab key or click ouside of the control.
- Subscribe to the DropDownClosed event and observe that the SelectedValue and the text are different.

Workaround:
void radMultiColumnComboBox1_DropDownClosed(object sender, Telerik.WinControls.UI.RadPopupClosedEventArgs args)
{
    this.radMultiColumnComboBox1.Text = this.radMultiColumnComboBox1.SelectedValue.ToString();
}

To reproduce:
- Add some items to the control and set the DropDownAnimationEnabled to false.
- Programmatically select the  third item
- Start the application, open the drop down and scroll up with the mouse - you will notice that the grid is not scrolled up.

Workaround:
Set DropDownAnimationEnabled to true.

When set the SelectedIndex property in the DropDownClosed event selected index is not set correctly.  

Workaround:
private void radMultiColumnComboBox1_DropDownClosed(object sender, Telerik.WinControls.UI.RadPopupClosedEventArgs args) 

{

this.radMultiColumnComboBox1.SelectedIndex = 0; 

this.radMultiColumnComboBox1.EditorControl.CurrentRowChanging += new CurrentRowChangingEventHandler(EditorControl_CurrentRowChanging); 

}

void EditorControl_CurrentRowChanging(object sender, CurrentRowChangingEventArgs e) 

{

e.Cancel = true; 

this.radMultiColumnComboBox1.EditorControl.CurrentRowChanging -= EditorControl_CurrentRowChanging; 

} 

When filtering is applied to RadMultiColumnComboBox editor in CellEditorInitialized event of RadGridView, the selected item is second one, if the new row is edited.

Workaround: change the event handler by adding the following lines of code in the end of the RadGridView1_CellEditorInitialized:

Dim value As Object = e.Row.Cells(e.ColumnIndex).Value
 
If value Is Nothing Then
    editor.EditorControl.CurrentRow = Nothing
Else
    editor.Value = e.Row.Cells(e.ColumnIndex).Value
End If

The last selected item is not tokenized when there isn't enough space, and it needs to move to the second line.

Title

KeyNotFoundException in DefaultAppearanceProvider.TryGetCurrentAnnotationAppearances when loading PDF with FreeText/Widget annotation containing invalid "/AP << /N 0 0 R >>" reference (likely macOS Preview-authored)

Product / Version

• Product: Telerik UI for WPF — RadPdfViewer / PdfProcessing (Telerik.Windows.Documents.Fixed.dll)
• Version: 2022.1.217.40
• Platform: .NET Framework 4.x, WPF, Windows

Summary

Loading a PDF containing an annotation with a broken appearance reference (/AP << /N 0 0 R >> — an indirect reference to object 0, which is reserved/invalid per the PDF spec) throws an unhandled KeyNotFoundException deep inside the rendering pipeline when the affected page is scrolled into view. This crashes the hosting WPF application, since the exception originates inside WPF's layout/render callback (OnRender) rather than during the initial PdfFormatProvider.Import() call, so it cannot be caught by application-level try/catch around import.

I found this appears to match a previously reported and fixed issue: "PdfViewer: KeyNotFoundException is thrown when loading a document with Free Text Annotation," fixed in Release 2024.3.924. I'd like confirmation this is the same root cause and whether 2024.3.924+ resolves it, or if this is a distinct case given the specific /N 0 0 R malformation I've isolated.

Steps to Reproduce

1. Load the attached PDF (page containing the annotation object shown below) into RadPdfViewer via PdfFormatProvider.Import() with ImportSettings = PdfImportSettings.ReadOnDemand.
2. Assign the resulting RadFixedDocument to RadPdfViewer.Document.
3. Scroll to the page containing the affected annotation.
4. Exception is thrown during WPF's render pass, not during import.

Full Stack Trace

System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
   at System.ThrowHelper.ThrowKeyNotFoundException()
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at Telerik.Windows.Documents.Fixed.Model.Annotations.MultiStateAppearances.get_Item(String stateName)
   at Telerik.Windows.Documents.Fixed.Utilities.Rendering.Annotations.DefaultAppearanceProvider.TryGetCurrentAnnotationAppearances(Annotation annotation, SingleStateAppearances& singleStateAppearances)
   at Telerik.Windows.Documents.Fixed.Utilities.Rendering.Annotations.DefaultAppearanceProvider.TryProvideAppearanceOverride(Annotation annotation, AnnotationAppearanceMode annotationAppearanceMode, FormSource& formSource)
   at Telerik.Windows.Documents.Fixed.Utilities.Rendering.Annotations.BaseAppearanceProvider.TryProvideAppearance(Annotation annotation, AnnotationAppearanceMode annotationAppearanceMode, FormSource& appearance)
   at Telerik.Windows.Documents.Fixed.Utilities.Rendering.Annotations.BaseAppearanceProvider.TryProvideAppearance(Annotation annotation, AnnotationAppearanceMode annotationAppearanceMode, FormSource& appearance)
   at Telerik.Windows.Documents.Fixed.Utilities.Rendering.FixedPageContentRenderingHelper.RenderNormalAnnotationAppearance(IFixedContentRenderer renderer, Annotation annotation)
   at Telerik.Windows.Documents.Fixed.UI.AnnotationAppearancesCanvas.DrawAppearance(DrawingContext drawingContext)
   at Telerik.Windows.Documents.Fixed.UI.AnnotationAppearancesCanvas.OnRender(DrawingContext dc)
   at System.Windows.UIElement.Arrange(Rect finalRect)
   at System.Windows.Controls.Canvas.ArrangeOverride(Size arrangeSize)
   at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
   at System.Windows.UIElement.Arrange(Rect finalRect)
   at System.Windows.ContextLayoutManager.UpdateLayout()
   at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
   at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
   at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
   at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)

Root Cause (identified via hex inspection of the source PDF)

The offending annotation object in the PDF:

181 0 obj
<< /AP << /N 0 0 R >>
   /M (D:20231128120931Z00'00')
   /Rect [ 67.664 412.788 527.774 446.2222 ]
   /AAPL:SFF true
   /F 4
   /DA (//Menlo-Regular 14 Tf 0 g)
   /AAPL:AKExtras
   << /AAPL:AKPDFAnnotationDictionary
      << /AP << /N 0 0 R >>
         ...

• /AP << /N 0 0 R >> is an indirect reference to object number 0, which is reserved by the PDF spec (head of the free-object list) and never resolves to a real object.
• The /AAPL:SFF, /AAPL:AKExtras, /AAPL:AKPDFAnnotationDictionary keys indicate this annotation was written by macOS Preview.app (Apple's proprietary annotation/markup extensions), consistent with a document that was signed or markup-annotated on a Mac before being distributed.
• DefaultAppearanceProvider.TryGetCurrentAnnotationAppearances does:

  singleStateAppearances = appearances[appearances.CurrentState];

with no existence/null check before indexing — when CurrentState doesn't resolve to a valid key (because the backing /N reference was never a valid object), this throws KeyNotFoundException uncaught.

Impact

This exception occurs during WPF's internal render callback, outside the call stack of the code that calls PdfFormatProvider.Import(), so it cannot be caught by a standard try/catch around import/load. It surfaces as a DispatcherUnhandledException on the UI thread and, without an application-level workaround, crashes the hosting application entirely.

What I'm asking Telerik to confirm

1. Is this the same root cause as the "KeyNotFoundException when loading document with Free Text Annotation" issue fixed in 2024.3.924, or a distinct case specific to the /N 0 0 R invalid-reference pattern?
2. Can you confirm 2024.3.924+ (or ideally your current latest) resolves this specific /N 0 0 R malformation, not just the FreeText-annotation case?
3. Is there a supported, non-reflection-based public API to validate/sanitize an annotation's appearance state before rendering, so we can defensively filter malformed annotations without waiting for a full version upgrade? (We are currently working around this via reflection into internal Appearances/MultiStateAppearances members, which is fragile across versions.)
4. Since TryGetCurrentAnnotationAppearances already has "Try" in its name implying safe failure, could this be hardened with a TryGetValue instead of the indexer, to fail gracefully rather than throw, for any similarly malformed future document?

The arrow button click does not work as expected in the latest release version. This is a regression in our latest 2026.2.702 release, where the AllowedClickButtons property is not initialized correctly. We are working on a fix! Please subscribe to this item, and you will receive an email notification when we introduce the fix.

In the meantime, you can apply the following workaround:

this.radDropDownList1.DropDownListElement.ArrowButton.AllowedClickButtons = MouseButtons.Left;

Or use v.2026.2.520, where the arrow button functions as usual.

We appreciate your patience and apologize for the inconvenience this issue may have caused. 

The Enabled property cannot be set in PropertyBuild if the RadTreeView is already data-binded via Property builder

Workaround:

Set the property at run-time.

To reproduce:


Add nodes to RadTreeView with at least 3 levels hierarchy. Set some of the last level nodes Visible property to false. Start the application. Expand some nodes and scroll. You will notice that the last item will change sometimes.


Workaround:
Set this.radTreeView1.TreeViewElement.AllowArbitraryItemHeight = true;
Use ItemHeight = 1, instead of Visible = false

The child nodes are aligned to the root nodes when ShowRootLines property is set to false.

To reproduce:
  radTreeView1.Filter = "new";
            radTreeView1.Nodes.Add("new Node");
            for (int i = 0; i < 1000; i++)
            {
                radTreeView1.Nodes.Add(new RadTreeNode("test"));
            }

Workaround:
            radTreeView1.TreeViewElement.Update(RadTreeViewElement.UpdateActions.Reset);

When an appointment has a very short duration (seconds-level, e.g., 1 second and 0 minutes), it does not appear in the RadPrintPreviewDialog. The appointment is visible in the scheduler UI but missing from the print preview.

For example:

To reproduce:

    Sub New()

        InitializeComponent()

        Dim intItem As New PropertyStoreItem(GetType(Integer), "Integer", 1)
        Dim floatItem As New PropertyStoreItem(GetType(Single), "Float", 1.0F, "Property storing a floating point value.")
        Dim stringItem As New PropertyStoreItem(GetType(String), "String", "telerik", "Property storing a string value", "Telerik")
        Dim fontItem As New PropertyStoreItem(GetType(Font), "Font", New Font("Arial", 12, FontStyle.Italic), "Property containing Font value")

        fontItem.Attributes.Add(New ReadOnlyAttribute(True))
        floatItem.Attributes.Add(New ReadOnlyAttribute(True))
        Dim store As New RadPropertyStore
        store.Add(intItem)
        store.Add(floatItem)
        store.Add(stringItem)
        store.Add(fontItem)
        Me.RadPropertyGrid1.SelectedObject = store
    End Sub

Try to edit either the "Float" or the "Font" property. The editor will be activated although it doesn't have to.

Workaround: cancel the Editing event

    Private Sub RadPropertyGrid1_Editing(sender As Object, e As PropertyGridItemEditingEventArgs)
        If e.Item.Name = "Font" Then
            e.Cancel = True
        End If 
    End Sub

An exception is thrown when loading a document:

FileNotFoundException: Could not load file or assembly 'Microsoft.Web.WebView2.WinForms, Version=1.0.3719.77, Culture=neutral, PublicKeyToken=2a8ab48044d2601e' or one of its dependencies. The system cannot find the file specified.

The following error occurs when closing Property Builder at design time: