Last Updated: 17 Apr 2024 14:45 by ADMIN
How to reproduce: set a size in the designer, when the form loads its size will not be the same as the one set

Workaround: set the size in the Load event of the ribbon form

private void Form_Shown(object sender, EventArgs e)
	this.Size = new Size(600, 600);
Last Updated: 25 Mar 2024 09:48 by ADMIN
Setting the ShowBorder property design time, will not serialize its value in the designer. Changing the form size, for example, will remove the setter of this property from the designer.cs file.
Last Updated: 13 Mar 2024 08:49 by ADMIN
Release 2024.1.312
I am using the Winforms 4.8 Nuget package. And just recently now when I make any edits to the form with a RadRibbonBar in the designer, the declare for that object in the designer.cs code changes from RadRibbonBar to DropDownPopupForm.
Last Updated: 21 Jun 2023 12:01 by ADMIN

The theme component is added to the form:

Here is the code:

Public Class RadRibbonForm1
    Sub New()


        Me.AllowAero = False

    End Sub

    Private Sub RadButtonElement1_Click(sender As Object, e As EventArgs) Handles RadButtonElement1.Click
        ThemeResolutionService.ApplicationThemeName = "Office2010Blue"
    End Sub
End Class

Last Updated: 09 Jun 2023 08:29 by ADMIN

In this case, the group is in collapsed mode. When we open its drop-down button to see the elements inside and afterward expand the form to see the whole group, the theme of the group is reset. Moving the mouse over the group will reset the theme.

Last Updated: 25 May 2023 08:13 by ADMIN

The caption text of the RibbonBarGroups disappears when switching themes runtime. The important part is that this behavior is observable when switching from the Office2010Blue theme to other themes. In this specific theme, the FillPrimitive holding the TextPrimitive (caption text) has the PositionOffset property set to 0,-1. This minus one pixel is messing up the layout during theme change.

What can be done as a workaround is to reset this property for every group. When the Office2010Blue theme is applied run this code:

private void radButton1_Click(object sender, EventArgs e)
    Office2010BlueTheme theme = new Office2010BlueTheme();
    ThemeResolutionService.ApplicationThemeName = "Office2010Blue";
    foreach (var item in this.ribbonTab1.Items)
        if (item is RadRibbonBarGroup)
            var group = item as RadRibbonBarGroup;
            group.Children[1].Children[0].PositionOffset = new SizeF(0, 0);


Last Updated: 27 Mar 2023 06:39 by ADMIN
Release R1 2023 SP1
1. Change the theme to FluentDark using the dropdown located at the very top left of the app form (it should say Fluent as default). 
2. Select the Administration View ribbon group, located at the very left of the form ribbon
3. Select any option from the dropdown menu that appears 
You should see that the borders around the ribbon groups appear, and  once the mouse hovers over a collection is 'refreshes' them and the issue is then not repeatable for that group of buttons (even after another theme change). As mentioned in the previous ticket, this issue is only repeatable once per application launch
Last Updated: 02 Feb 2023 09:34 by ADMIN
Release R1 2023
In this case, the RadRibboBar collapsed. So when we add a group run-time, its theme is not applied.
Last Updated: 01 Nov 2022 15:11 by ADMIN
Release R3 2022 SP2

To reproduce:

1. Add a form with a RadRibbonBar and add some tabs

2. Create a second form that inherits the first one

3. Open the second form at design time and add a few items to the application menu.

Expected: either the applied changes in the derived form should be serialized properly or the ribbon in the derived form should be locked for such changed.

Actual: even though the menu items are added in the designer and you can see them, after restarting the designer, they are not shown in the application menu anymore. You can see that they are still available in the Designer.cs but they are not added to the application menu. The same behavior is observed if you add tabs and groups with different elements.

Last Updated: 28 Oct 2022 12:45 by ADMIN
Created by: Alain
Comments: 1
Category: RibbonBar
Type: Feature Request
Improve the Accessibility functionality supported by RadRibbonBar, its elements and their properties to accessibility clients. Other elements than RadRibbonBar and RadButtonElement (RibbonTab and RadRibbonBarGroup elements) should be hittable, so tracking with mouse is available.The elements should be also exposed in a hierarchical way in the accessibility tree, including RadRibbonGroup elements.
Last Updated: 12 Oct 2022 13:07 by ADMIN
Release R3 2022 (LIB 2022.2.711)

Follow the steps:

1- Add RadRibbonBar1 to the form. The program compiles successfully.
2- Add RibbonTab1 to the RibbonBar. The program compiles successfully.
3. Add RadRibbonBarGroup1. The program does not compile and the mentioned error appears.

Error 1 Invalid Resx file. Could not load type System.DelegateSerializationHolder, Telerik.WinControls.UI, Version=2022.2.622.40, Culture=neutral, PublicKeyToken=5bb2a467cbec794e which is used in the .RESX file.  Ensure that the necessary references have been added to your project. Line 142, position 5. C:\Projects\1570764TestRibbonResx\1570764TestRibbonResx\RadForm1.resx 142 5 1570764TestRibbonResx

Last Updated: 02 Jun 2022 06:38 by ADMIN
Release R2 2022 SP1


please see the attached sample and screen shot.

If application with Ribbon Bar is moved to a high dpi display (or started on a 4K display), two issues happen:

  1. The title bar is not scaled (font) and has an ugly black line
  2. The drop down element font is not scaled (the list itself is correct)


Last Updated: 02 Jun 2022 06:33 by ADMIN
Release R2 2022 SP1
Created by: Dess | Tech Support Engineer, Principal
Comments: 0
Category: RibbonBar
Type: Bug Report
Use the arrow on the right side of RadRibbonBar to collapse it. When click some of the tabs to show the popup.

Workaround: specify a minimum height for the popup:
        protected override void OnLoad(EventArgs e)
            radRibbonBar1.Expanded = false;

            RibbonBarPopup pop = this.radRibbonBar1.RibbonBarElement.Popup;
            pop.PopupOpened += pop_PopupOpened;

        private void pop_PopupOpened(object sender, EventArgs args)
            RibbonBarPopup pop = sender as RibbonBarPopup;
            pop.MinimumSize = new Size(0, 150);
Last Updated: 24 Jan 2022 17:57 by ADMIN

1. Enable Backstage view mode

radRibbonBar1.ApplicationMenuStyle = Telerik.WinControls.UI.ApplicationMenuStyle.BackstageView;

2. Add BackstageButtonItem and BackstageTabItem to the Application Menu.

3. Run the program and run the accessibility tool "inspect.exe"

4. Select MSAA in "inspect.exe" and hover over a Backstage item.

As you can see in the attached screenshot BackstageButtonItems and BackstageTabItems are not accessible by inspect.exe.

Last Updated: 16 Jun 2021 11:34 by ADMIN
Please refer to the attached gif file illustrating how MS Word works. It would be good to provide a convenient UI for navigating through the tabs when the ribbon is shrunk.
Last Updated: 10 Jun 2021 12:47 by ADMIN
Release R2 2021 SP1

Please refer to the attached gif file for better illustration.


    Private Sub RadGalleryElement_DropDownClosed(sender As Object, args As RadPopupClosedEventArgs)
        For Each item As RadGalleryItem In Me.RadGalleryElement1.Items
            item.VisualState = ""
    End Sub

Last Updated: 09 Jun 2021 13:25 by ADMIN
Release R2 2021 SP1
Created by: Thomas
Comments: 1
Category: RibbonBar
Type: Bug Report

Hello Telerik Team,

i hope you can help us with an scaling Problem on submenues.

On highdpi mode the width of submenues on the application menues grows.

We tried some ways to fix the size on dropdownopened event.

More details in attached gif and project.


Last Updated: 14 Apr 2021 15:56 by ADMIN
Release R2 2021

Hi Telerik Support,

Here is a description of the environment I work with:


- Visual Studio 2019 (version 16.9.3)

- NuGet package is UI.For.Winforms.AllControls.Net50 (v2021.1.326)

- Project is a .NET5.0 class library.


When trying to add a RadDropDownListElement to a RadRibbonBarGroup, Visual Studio seems to encounter an error and a window pops up with the message "The connection to the server has been lost". Adding other types of elements to the RadRibbonBarGroup seems to work properly (I managed to add buttons without any issues).

I will attach a screenshot of the issue.

Thanks for your help !

Last Updated: 24 Mar 2021 11:28 by ADMIN


When using radsplitbutton in a ribbon, when the ribbonbargroup is collapsed due to a form too small, then the click event on the button part is not fired.

When clicking the button, the radsplitbutton look like it is "checked" instead, the popup is not open.

This has been tested in 2021.1.204.40, I apologize if this has been fixed in between.



Last Updated: 23 Feb 2021 01:43 by MyeongSeong

By default, the ImagePrimitive in a ribbon button is auto sized. If you want to disable the AutoSize property of the image and specify a specific Size, the AutoSize property gets serialized in the designer, but the Size is not. This leads to missing image after reopening the designer.

After saving the changes and reopening the designer the image is missing since its Size property is not serialized:



1 2 3 4 5 6