There is a big problem with Telerik controls when using national resource files.  Switching from one language to another and again sometimes destroys the user interface. It especially concerns RadCheckBox control. Text, tooltip and probably other properties from one control appear in other control etc. I think it can be a general problem because I also noticed that sometimes Image from one RadButton control appears in other button.

I prepared a set of images which show how it happended in my case. Switching from Default language to Polish language and again and then adding and removing new RadCheckBox completly destroyed user interface in my sample UserControl. This new RadCheckbox was created as a copy of existing RadCheckBox what may be a clue.

I also attached VS2019 project with my sample UserControl.

Best regards,

Andrzej

(This request may be specific to VS solutions which produce only DLLs, and not to ones which create a .exe.)

At the moment, the default behaviour for everything else in my VS project is to not produce warnings unless something might be wrong, which I may need to action.

WinForms,as of the latest release (2025) is the only thing which produces warning messages where there is not problem, which is not very tidy. I only want to see things in the build output which need my attention, defintely not 'happy' messages, or warnings which are not needed.

Currently, for each project in my solution, I get a message like:

1>  [Telerik and Kendo UI Licensing]
1>        Valid Telerik UI for WinForms license found. Make sure the main application also references Telerik.Licensing when using a class library.

...but I have a valid licence, and everything is OK. No action is needed.

Your support suggested adding...

  <TelerikLicensingVerbosity>quiet</TelerikLicensingVerbosity>

...to each project in my solution, but that still produces the above build message.

A polite solution would be to turn-off ALL such warning messages, and let me switch them ON when needed. Preferably via a setting somewhere, not by editing the VS project file, which means unloading, editing the project file, and realoading each of many  projects.

(Visual Studio 2026, not currently an option in the drop-down below)

I am working with the RadListView and noticed that its right and bottom border gets clipped at some (not all) width/heights and some scale factors (most notably 150% and 175%). This problem does not occur with the basic System.Windows.Forms.ListView.

Here is the code that I have wrote to replicate this problem with both the WinForms list view and the RadListView. 

      private void InitializeComponent()
      {
              this.listView1 = new System.Windows.Forms.ListView();
              this.radListView1 = new Telerik.WinControls.UI.RadListView();
              ((System.ComponentModel.ISupportInitialize)(this)).BeginInit();
              this.SuspendLayout();

              this.listView1.HideSelection = false;
              this.listView1.Location = new System.Drawing.Point(155, 10);
              this.listView1.Name = "listView1";
              this.listView1.Size = new System.Drawing.Size(135, 175);

              this.radListView1.Location = new System.Drawing.Point(5, 10);
              this.radListView1.Name = "radListView1";
              this.radListView1.Size = new System.Drawing.Size(135, 175);
              this.radListView1.UseCompatibleTextRendering = true;

              this.Controls.Add(this.radListView1);
this.Controls.Add(this.listView1);

              this.Name = "RadForm1";
              this.Text = "RadForm1";
              ((System.ComponentModel.ISupportInitialize)(this)).EndInit();
              this.ResumeLayout(false);
      }

Here is a screenshot of the dialog when the scale factor is at 100% (left is the RadListView component):

and here is a screenshot of when my display is scaled at 150% (left is the RadListView component):


To replicate: run the project attached, both at 100% scaling and 150% scaling. 

Thanks!

Contrary to Telerik.WinControls.UI.Barcode.QRCode, Telerik.WinControls.UI.Barcode.Symbology.QRCode creates invalid (unscannable) QR-Codes if the message contains umlauts when using ECIMode.UTF8.

We are using Symbology.QRCode, because we use it in columns of a RadGridView.

I've attached two example QR-Codes of the value "Bär", one using Barcode.QRCode, and the other one using Barcode.Symbology.QRCode.

Note: I have one scanner that can scan some of the Barcode.Symbology QR-Codes with umlauts.

Provide an AI assistant for code generation with the Telerik UI for WinForms controls. 

Such as Telerik Blazor AI Coding Assistant

Using specifically Win11 Compact DARK theme has additional space compared to the Win11 Compact LIGHT theme. See the pictures.

• On Light theme there are 4 pixels between the form border and the top border of a tab.
• On Dark theme there are 12 pixels between the form border and the top border of a tab.

In my opinion the dark theme has a wrong height here and the light theme is correct, especially compared to other themes, even Office 2019 for example.

Light theme:

Dark theme:

In the Visual Theme Builder (fresh installed Telerik UI for WinForms) you'll get an error because the directory "VbsRecoveryData" seems to be missing. Creating the directory before "package.Compress(path)" fixes this for me.

Error is received when click on button. Reproduced randomly on different machines.

Hello,

We encountered problems with configuration of the toolbox in Visual Studio 2022 when out-of-proc designer is active.
More information about the usage and reason for the out-of-proc designer: https://github.com/dotnet/winforms/blob/main/docs/designer/designer-selection.md

Tested environment:
- Visual Studio 2022
- .NET Framework 4.7.1
- 32-bit application
- Windows 11 Pro
- Telerik UI For Winforms 2025.2.520.462

When trying to add a rad control from the toolbox the error in attachment occurs.

Workaround:
- Disable the out-of-proc designer in the project file:

<UseWinFormsOutOfProcDesigner>False</UseWinFormsOutOfProcDesigner>

Since 2025 Q2 you'll get this error message when you try to open a flyout on a control that is not a Form. This does not happen with 2025 Q1.

Might be related: https://feedback.telerik.com/winforms/1688619-radform-clientsize-on-inherited-radform-is-broken

However, this time I have no patch / workaround. I have not the time to investigage deeper at the moment, so update to Q2 not possible for me at the moment.

Steps to Reproduce:

1. Create a new WinForms application targeting .NET 9.

2. Add a RadStatusStrip to the main form.

3. Run the application.

4. Snap the form to the left or right edge of the screen (using Windows Snap).

5. Minimize the form.

6. Restore the form.

Expected Behavior:
The form should maintain its original size and remain fully visible on screen after being restored.

Actual Behavior:
Every time the form is minimized and restored, it increases in height. After a few cycles, the bottom part of the form — including the RadStatusStrip — becomes hidden behind the Windows taskbar (Start menu).

Additional Info:

• The issue only occurs when a RadStatusStrip is added to the form.

• The issue does not occur when using a standard StatusStrip from WinForms.

• The problem occurs consistently and can be reproduced easily.

• Tested both in debug mode and with a compiled executable.

Attachments:

• Screenshots (before and after restore).

• Sample reproduction project (if needed).

  This is only repeated in windows 10

   

When trying to open the QuickStart solution from 

C:\Program Files (x86)\Progress\Telerik UI for WinForms 2025 Q1\Examples

installation folder, the following error appears:

Visual Studio 2022 crashes when working with a solution containing two WinForms projects:

• Project 1: WinForms (.NET 9) with Telerik
• Project 2: WinForms (.NET 6) without Telerik

Steps to Reproduce:

1. Create a new solution in Visual Studio 2022.
2. Add two WinForms projects:
   • Project 1: WinForms (.NET 9) with Telerik
   • Project 2: WinForms (.NET 6) without Telerik
3. Open the WinForms designer for a form in Project 1 (Telerik, .NET 9).
4. Without closing the designer, open the WinForms designer for a form in Project 2 (.NET 6, no Telerik).
5. Switch to the code view of the form in Project 2.
6. Switch back to the WinForms designer in Project 2.

Expected Result:
Visual Studio should smoothly switch between code and designer views without issues.

Actual Result:
Visual Studio freezes and crashes after switching back to the WinForms designer in Project 2.

Environment:

• Visual Studio 2022
• Windows Version: (Windows 11 x64)
• Telerik WinForms Version: (2025.1.211)

Additional Notes:

• The issue seems to be related to handling different .NET versions and Telerik components in the same solution.
• The crash occurs consistently when following the steps above.
• No explicit error messages are shown before Visual Studio closes.

Hello team!

I've found a misbehavior on RadForm when setting the size.

When you set the Size of the Form before it actually has shown then it will do some re-calculation, change the form size several times, and ending up in a too big size. The behavior is different to a original Form and that's why I'd treat this as bug.

The first screenshot shows a RadForm that set itself to ClientSize = 500; 500 on the constructor, like usual. It ends up in a size slightly bigger then defined.


This second screenshot shows a RadForm that set itself to ClientSize on "Shown". It ends up in having the correct size.

Whenever you set a breakpoint to the method "Form1_Resize" you can capture that the first time the Size of the RadForm get changed is our "ClientSize = new Size(500, 500)". Then the Size get changed two times by RadForm itself to something slightly smaller. Lastly the Size get changed by RadForm another time, but this time slightly bigger

This behaviors can lead to inconsistent UI size, e. .g small spaces when using AutoSize = true in certain cases. But yet didn't figured completely out when exactly it happens, just that it comes from this slightly increased Size of RadForm.

Can you please take a look to it and, if it is one, report it as bug?

Thank you very much!

Regards,
Pascal