Hi,

I was previously developing with Telerik UI for WinForms 2025 Q3. Recently, I installed the latest version (2025 Q4) using the MSI installer and then manually updated the NuGet packages in my project to complete the upgrade without using the Update Wizard. Everything works fine now.

However, every time I open the project in Visual Studio, I still see the notification:

"You are using an older version of Telerik UI for WinForms for this project. There is a new version available for this computer. Update Now"

Is there a way to disable or hide this notification after manually updating the NuGet packages?

Thanks in advance!

¡Hi everyone! Is there a possibility to have a RadContexMenu with rounded corners ?
I already change the styles via theme, but when I open the context menu, it has some white square corners behind.

The version I have right now is 2016 SP1

Our application doesn't explicitly set a default theme so it defaults to ControlDefault.
One screen uses the MaterialBlueGrey theme, so I wanted the related MessageBoxes to also use that theme.

Per the instructions I used the following code:

RadMessageBox.SetThemeName("MaterialBlueGrey");
RadMessageBox.Show("MESSAGE");
RadMessageBox.SetThemeName("ControlDefault");

The problem is that, although the overall look goes back to the default theme, some elements stay with the MaterialBlueGrey theme. For example: the button height & caption font.

I tried all these with the same result:

RadMessageBox.SetThemeName("");
RadMessageBox.ThemeName = "";
RadMessageBox.ThemeName = "ControlDefault";

I have a situation where I have code that executes when the Selected Node  is changed.

SelectedNodeChanged

The code in the SelectedNodeChange adds controls to some FlowLayoutPanel.

When a user clicks on a node, you can see the controls being added to the control

but the RadTreeView allows the user to select another node eventhough the SelectedNodeChange event has not finished, which

is now causing issues with the FlowLayoutPanelshowing duplicate controls.

If user waits until all controls are in the FlowLayoutPanel, and then selects another node, everything works as expected.

None of the code that adds the controls to the FlowLayoutPanel are Asynchronous.

I DO NOT have Multiselect = true.

** I have noticed that the RadTreeView acts as though it is Asynchronous when filling it.  I have code that fills the nodes and you can select the nodes and see the nodes being added behind the scenes. 

Maybe control is Asynchronous when changing selected nodes?

Hello,

When I drag and drop an item in PageView, I would like it to create a copy of the item (page) when holding the Control key—either within the same PageView or between different PageViews.

Could you help me achieve this?

Thank you.

When using RadOpenFolderDialog, some people see their mapped drives and some do not. This includes people within my office would should all have their mapped drives created the same way.

Is there a way that I can ensure RadOpenFolderDialog always sees the mapped drives of the user?

Hello, I'm trying to display a chart by salesperson, grouped by month, showing the total sales amount. I've attached a photo. I've tried many things without success. Thank you for your time.

I work with WinForms and VB.NET

Hello,

we have an application using Telerik version 2021.3.1123.40. It is not the first time these errors were reportet, but I have no methode to reproduce it at the moment. The chain of Events for both errors is, that RadGridView.FilterChanged-Event is called, from there we call our method "UpdateProzessschritte" (UpdateProcessSteps), which does a BeginUpdate and EndUpdate of the grid. When EndUpdate is called, the 2 errors orccured under certain, unknown conditions.

1. ERROR|TBM_HAProzessPlugin.MainForm|1|(null)| In Modul TBM|DNA - Digitaler Netzanschluss ist ein Fehler aufgetreten. System.InvalidOperationException: Die Auflistung wurde geändert. Der Enumerationsvorgang kann möglicherweise nicht ausgeführt werden.
      bei System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
      bei System.Collections.Generic.List`1.Enumerator.MoveNextRare()
      bei System.Collections.Generic.List`1.Enumerator.MoveNext()
      bei Telerik.WinControls.UI.DataGroup.<GetEnumerator>d__7.MoveNext()
      bei Telerik.WinControls.UI.GridViewGroupRowInfo.get_ChildRows()
      bei Telerik.WinControls.UI.GridViewRowInfo.HasChildRows()
      bei Telerik.WinControls.UI.GridTraverser.CanStepInHierarchy()
      bei Telerik.WinControls.UI.GridTraverser.StepInHierarchy()
      bei Telerik.WinControls.UI.GridTraverser.MoveNextCore()
      bei Telerik.WinControls.UI.GridTraverser.MoveNext()
      bei Telerik.WinControls.UI.GridTraverser.GoToRow(GridViewRowInfo row)
      bei Telerik.WinControls.UI.BaseGridNavigator.ProcessEventCore(GridViewEvent eventData)
      bei Telerik.WinControls.UI.BaseGridNavigator.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
      bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
      bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
      bei Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
      bei Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
      bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
      bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewTemplate template, GridViewEvent eventData, Boolean postUI)
      bei Telerik.WinControls.UI.GridViewTemplate.DispatchEvent(GridViewEvent gridEvent, Boolean postUI)
      bei Telerik.WinControls.UI.GridViewTemplate.DispatchDataViewChangedEvent(Object sender, DataViewChangedEventArgs args)
      bei Telerik.WinControls.UI.GridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.MasterGridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.MasterGridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate()
      bei Telerik.WinControls.UI.RadGridView.EndUpdate()
      bei TBM_HAProzessPlugin.MainForm.UpdateProzessschritte(RadGridView radGridView, RadDiagram radDiagram, Dictionary`2 prozessDauerListe, List`1 schritte) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 510.
      bei TBM_HAProzessPlugin.MainForm.rgvHAAkten_FilterChanged(Object sender, GridViewCollectionChangedEventArgs e) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 442.
   
   [Translation]: Collection was modified; enumeration operation may not execute
   
   
   
2. ERROR|TBM_HAProzessPlugin.MainForm|1|(null)| In Modul TBM|DNA - Digitaler Netzanschluss ist ein Fehler aufgetreten. System.ArgumentException: Ein Element mit dem gleichen Schlüssel wurde bereits hinzugefügt.
      bei System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
      bei System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
      bei System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
      bei Telerik.WinControls.Data.GroupBuilder`1.Perform(IReadOnlyCollection`1 items, Int32 level, Group`1 parent)
      bei Telerik.WinControls.Data.GroupBuilder`1.get_Groups()
      bei Telerik.WinControls.Data.RadDataView`1.get_Groups()
      bei Telerik.WinControls.UI.GridViewInfo.Refresh()
      bei Telerik.WinControls.UI.GridViewInfo.get_ChildRows()
      bei Telerik.WinControls.UI.GridViewTemplate.get_ChildRows()
      bei Telerik.WinControls.UI.ViewInfoTraverser.SetCollectionForStage(Boolean initializeCollection)
      bei Telerik.WinControls.UI.ViewInfoTraverser.ChangeCollectionForward()
      bei Telerik.WinControls.UI.ViewInfoTraverser.MoveNextCore()
      bei Telerik.WinControls.UI.ViewInfoTraverser.MoveNext()
      bei Telerik.WinControls.UI.GridTraverser.MoveNextCore()
      bei Telerik.WinControls.UI.GridTraverser.MoveNext()
      bei Telerik.WinControls.UI.GridTraverser.GoToRow(GridViewRowInfo row)
      bei Telerik.WinControls.UI.BaseGridNavigator.ProcessEventCore(GridViewEvent eventData)
      bei Telerik.WinControls.UI.BaseGridNavigator.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
      bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
      bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
      bei Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
      bei Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
      bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
      bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewTemplate template, GridViewEvent eventData, Boolean postUI)
      bei Telerik.WinControls.UI.GridViewTemplate.DispatchEvent(GridViewEvent gridEvent, Boolean postUI)
      bei Telerik.WinControls.UI.GridViewTemplate.DispatchDataViewChangedEvent(Object sender, DataViewChangedEventArgs args)
      bei Telerik.WinControls.UI.GridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.MasterGridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.MasterGridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
      bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate()
      bei Telerik.WinControls.UI.RadGridView.EndUpdate()
      bei TBM_HAProzessPlugin.MainForm.UpdateProzessschritte(RadGridView radGridView, RadDiagram radDiagram, Dictionary`2 prozessDauerListe, List`1 schritte) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 510.
      bei TBM_HAProzessPlugin.MainForm.rgvHAAkten_FilterChanged(Object sender, GridViewCollectionChangedEventArgs e) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 442.
   
   [Translation]: Item with Same Key has already been added

Do you have any ideas which causes could lead to this exceptions and how to fix it? Or is this a known problem which was already fixed in later versions?

I have a WinForms .NET project running Telerik Version 2022.1.222.40 (I know its old but its what I have). Everything is working as expected and the application has no apparent problems at runtime.

After migrating to VS 2022 I am seeing various errors in the output. These errors appears to correspond with the loading of various Telerik components, the first of which is the theme but others include the Pageview control.

The following error is repeated at each of these times:-

Microsoft C++ exception: EEFileLoadException at memory location 0x000000ED451FB450.

Microsoft C++ exception: [rethrow] at memory location 0x0000000000000000.

Any help appreciated.

G

Hello,

VirtualKeyboard (WinForms) on Windows 11 with touchscreen monitor when key touched with finger quite often keeps stuck and repeats input until another key is pressed or mouse leaves that button.

Thats new for Windows 11 (on previous versions that was not happening).

It only happens when physically touched on touchscreen and in Windows 11. If pressed with mouse it does not happening.

To reproduce can be used Telerik demo app > Virtual Keyboard > First Look (please see attached image of my test, button g is pressed and released, but gggggg input keeps appending)

Environment Windows 11 Pro 24H2 with touchscreen monitor.

Also tested on my app with Telerik UI For WinForms 2025.3.812 (the same outcome).

Is there plans to fix this? Or maybe there is a workaround?

Mindaugas