Won't Fix
Last Updated: 21 Apr 2023 13:54 by ADMIN
A binding error appears in the VS Output pane on startup of the RadOpenFileDialog. The error states the following:
System.Windows.Data Error: 26 : ItemTemplate and ItemTemplateSelector are ignored for items already of the ItemsControl's container type RadBreadcrumbBarItem
The error can be ignored because it doesn't break the file dialog functionalities.
Won't Fix
Last Updated: 19 Jan 2023 14:25 by ADMIN
The mouse-over highlight color is not applied to the correct row when the rows are navigated via the keyboard arrows.
Won't Fix
Last Updated: 30 Nov 2022 16:33 by ADMIN
Clicking on a RadDropDownButton in the Visual Studio 17.4.0 designer makes it stop responding.
Won't Fix
Last Updated: 06 Oct 2022 09:48 by ADMIN
Can be observed in FirstLook demo of the RadGridView.
While resizing the demos window, radgridview's horizontal scrollbar might flicker when demos viewport size is close to the gridview size.
Won't Fix
Last Updated: 06 Oct 2022 09:20 by ADMIN
Created by: Martin Ivanov
Comments: 1
Category: Docking
Type: Bug Report
A memory leak related to the automation peers of the RadPane and RadPaneGroup appears when you close a pane (using its Close button) even if you call its RemoveFromParent() method.

To work this around disable the automation peers. To do so please set the static AutomationManager.AutomationMode property toAutomationMode.Disabled.
public MainWindow()
    AutomationManager.AutomationMode = AutomationMode.Disabled;

The issue originates from ItemsControlAutomationPeer. It is reported to Microsoft in their old connect portal here =>

Won't Fix
Last Updated: 02 Jun 2022 15:14 by ADMIN
InvalidOperationException regarding QuickStyle Freezable is thrown when the control is opened in new STA thread.
Won't Fix
Last Updated: 03 May 2022 13:40 by ADMIN
DataContext of rows is sometimes null when UI virtualization is enabled in the Flat group render mode.

The issue appears also without UI virtualization and in the Nested mode. It happens on ItemsSource reset of RadGridView, in case the old ItemsSource value wasn't empty. The DataContext is set to null for a brief moment before the old visuals are removed from the view, which causes issues in some scenarios related to CellTemplate
Won't Fix
Last Updated: 04 Apr 2022 12:38 by ADMIN


I am currently having issues with RadGridView's group footer: I am trying to add a button to the footer template which is supposed to trigger a command which in turn needs some info on the group it was triggered from*.

Since (unlike the header) there does not seem to be any info on the group available directly within the GroupFooterTemplate, I am pulling the group info from the parent GridViewGroupFooterRow:

                <telerik:GridViewDataColumn [...]>
                            <Button Command="{Binding DataContext.ShowFooterGroupCommand, RelativeSource={RelativeSource AncestorType=telerik:RadGridView}}"
                                    CommandParameter="{Binding Group.Key, RelativeSource={RelativeSource AncestorType=telerik:GridViewGroupFooterRow}}" />

This is working great as long as the RadGridView does not use Row virtualization. However, when I turn on Row virtualization and scroll around for a bit, the value I get passed as the CommandParameter is more or less random and has nothing to do with the group my button is actually located in.

I attached a small example project (.Net 6 but our app uses 4.8 so I set that as the Framework below) for you to try it yourself. Just scroll around and click the buttons while watching the debug output window. You will see that the groups in the output window will not match the group where you actually clicked the button after some scrolling.

Expected Behavior

Even when virtualizing, the Group key returned when binding to GridViewGroupFooterRow.Group(.Key) should reliably return the key of the actual group my button is placed in. It would be even better if it was somehow possible to get the group directly, without having to resort to FindAncestor.

Simon Müller
Hofmann Fördertechnik GmbH


* Basically I am trying to give the user a possibility to add new items to the individual groups and I don't want to add the button to the group header since that makes it too easy to accidentally hit the header's RadToggleButton, collapsing the group.

Won't Fix
Last Updated: 20 Dec 2021 15:51 by Stenly
When clicking the remove button on an item, which is present more than once in the selection textbox, the first occurrence will be removed, rather than the corresponding item.
Won't Fix
Last Updated: 14 Jul 2021 14:22 by ADMIN
The designer of VS crashes with a "Key cannot be null" when custom markup extension is used in Style Setter. This reproduces in the sample app attached in the blog (http://www.telerik.com/blogs/bring-office-2016-inspired-style-to-your-app-with-ui-for-wpf) on the TextBlock of the RabRadioButton HeadingStyle (snapshot attached) if you open MainWindow in Designer. Runtime everything works as expected.
Won't Fix
Last Updated: 16 Jun 2021 14:03 by ADMIN
When the RadWindow is declared in XAML and is used as a main window, it won't show in the designer by simply merging the required theme resources and defining an implicit style based on the RadWindowStyle.

Tested with 16.8.4 - works as expected. Updated to 16.9.0 to match the client's setup and managed to reproduce the issue. The issue is reproducible also with the 16.10.0 version of Visual Studio.

Won't Fix
Last Updated: 10 Feb 2021 09:59 by ADMIN
The RadGridView's is bound to an empty DataView and grouped by a GridViewComboBoxColumn. When adding items during runtime, setting the SelectedItem in code or selecting through the UI -> the SelectedItem remains null. 
Won't Fix
Last Updated: 16 Sep 2020 11:25 by ADMIN

The check mark of the RadioButton is misaligned when DPI settings are set to a higher than the default value, e.g. 125%.

The problem can easily be reproduced using the Telerik UI for WPF Demo application:

Won't Fix
Last Updated: 29 May 2020 08:46 by Petar
Cannot parse values when DisplayFormat is set to Long and AllowParsingWithoutSeparator is True.
Won't Fix
Last Updated: 26 May 2020 15:27 by Petar

" Collection was modified; enumeration operation may not execute.'" - The exception is observed when the CLR exceptions are enabled from Visual Studio. 


The Ellapsed event handler of the Timer is executed in background thread but modifying chart data in a background thread is considered bad practice which is not supported by our component. This is the reason we are declining this bug report.

General solution is to schedule the data update to happen on the UI thread with Dispatcher. When in ViewModel, the following code can be used:

        private void OnTimerElapsed(object sender, ElapsedEventArgs e)
            ViewModelBase.InvokeOnUIThread(() =>
                for (int i = 0; i < Items.Count; i++)
                    Items[i].X += (_random.NextDouble() - 0.5) * 0.1;
                    Items[i].Y += (_random.NextDouble() - 0.5) * 0.1;
Won't Fix
Last Updated: 12 May 2020 08:22 by Hans
Tab selection does not work in the VS designer when switching between different views.
Won't Fix
Last Updated: 30 Mar 2020 10:10 by ADMIN
The panel allocates empty space for items that are hidden by setting their Visibility to Collapsed. Such items should be ignored when the panel arranges its items.

To work this around, instead of the Visibility property, you can remove and add the items in the ItemSource collection whenever you need to toggle their visibility.
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