1. Create clean WinForms .NET Framework project.
2. Add Telerik UI for WinForms 2026.2.520.462.
3. Create BaseForm : RadForm.
4. Add RadStatusStrip to BaseForm.
5. Create inherited form RadForm1 : BaseForm.
6. Open inherited form in Visual Studio designer.
7. Designer crashes with NullReferenceException in Telerik.WinControls.UI.Design.RadControlDesigner.OnSetCursor.
8. Remove/comment RadStatusStrip from BaseForm.Designer.cs.
9. Designer opens successfully.
Sample project attached.
Hi, Jakub,
Thank you for providing a project. However, when I open the RadForm1 at design time using the specified 2026.2.520 version, I am not able to receive any issues. The VS designer opens successfully, see the image below:
Here is the BaseForm as well:
The form also shows normally when I run the project. I removed the commented code for the StatusStrip so that it appears on the form.
Am I missing something in reproducing the issue? On my side, I am using Visual Studio 2026.
Regards,
Nadya | Tech Support Engineer
Progress Telerik