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:

RadDropDownList - There is an empty line at the bottom of drop down list if you close drop down by arrow button.

Steps to reproduce :

Creating the application:

    New > Project > RadControls Windows Forms Application
    A wizard appears; the RadControls for Winforms version is selected (InstallFolder, not GAC)
    No components nor Themes were selected
    Code changed from:

public partial class Form1 : Form
to
public partial class Form1 : RadForm
The application consisted of a single drop down on the RadForm.The drop down DropDownStyle property changed to "DropDownList". The drop down had enough items to cause the scrollbar to occur.
No other properties from either form or drop down were changed.

The attached errorsteps.png are split into the following steps:

    Application opened
    Scroll down to the last item
    Select the item
    Open the drop down and scroll back to the top of the list; click the down arrow button to close the drop down
    Open the drop again.

FIX. RadContextMenu/RadMenu - animations does not perform correctly on Windows 8

WORKAROUND

Execute ThemeResolutionService.AllowAnimations = false; before the context menu is opened and then Allow animations again when the context menu is closed

To reproduce:
- Add four buttons to a RadForm
- On each button click use ThemeResolutionService to change the theme
=> the form size increases in height

Workaround:
Set the MaximumSize of the form to the current form size prior changing the theme and then remove this setting:
private void radButton1_Click(object sender, EventArgs e)
{
    this.MaximumSize = this.Size; ;
    ThemeResolutionService.ApplicationThemeName = "Office2010Blue";
    this.MaximumSize = Size.Empty;
}

When you focus a RadTextBox you will notice the keyboard button that popups next to the focused control. However, for the RadAutoCompleteBox this keyboard button does not show.

Workaround: show it manually on the GotFocus event and hide it on the LostFocus event 

private void radTextBox1_GotFocus(object sender, EventArgs e)
{
    string progFiles = @"C:\Program Files\Common Files\Microsoft Shared\ink";
    string keyboardPath = Path.Combine(progFiles, "TabTip.exe");
    Process.Start(keyboardPath);
}
 
private void radTextBox1_LostFocus(object sender, EventArgs e)
{
    var procs = Process.GetProcessesByName("TabTip");
    if (procs.Length != 0)
        procs[0].Kill();
}

To reproduce:
this.radTextBoxControl1.Text = "dog and blue glue";
this.radTextBoxControl1.Size = new Size(50, 65);
this.radTextBoxControl1.Multiline = true;

Workaround:
use RadTextBox.

To reproduce:
public Form1()
{
    InitializeComponent();

    this.radTextBox1.Text = "abcd";
    this.radTextBox2.Text = "abcd";
    this.radTextBoxControl1.Text = "abcd";
    this.radTextBoxControl2.Text = "abcd";

    this.radTextBox2.Multiline = true;
    this.radTextBoxControl2.Multiline = true;

    this.textBox1.Text= "abcd";
    this.textBox2.Text= "abcd";
    this.textBox2.Multiline = true;
}

Workaround: set the Multiline property to true in the Form.Load event.

Second workaround: this.radTextBox2.TextBoxElement.TextBoxItem.Margin = new Padding(-2, 0, 0, 0);

1. Add RadDropDowlList in form. 
2. Open the items collection and add some items. 
3. After that set the Selected property of one item to true and click OK. 
4. You will see that the change is not saved.

Workaround: 
Set the selected item at run time.

Workaround:
            
            this.radDropDownButton1.DropDownButtonElement.DropDownMenu.PopupElement.AutoSize = false;   
            this.radDropDownButton1.DropDownButtonElement.DropDownMenu.PopupElement.Size = new Size(300, 300);