Unplanned
Last Updated: 16 Oct 2026 15:05 by ADMIN

My users use Tab to focus the masked textbox and when they start typing (its content was highlighted because of getting focus with Tab), that typing action does not put the range (caret) in the correct place - it remains at position 0 rather than going to position 1.

For example, in the below phone mask they type "9" and then "0" and I would expect to get "90" but I get "0".

---

ADMIN EDIT

A workaround is to collapse the range when the input gets focus:

@inject IJSRuntime JsInterop

<input />
<span @onfocusin="@CollapseInputSelection" @ref="@ParentElem">
    <TelerikMaskedTextBox Mask="+1 (000) 000-0000"
                          IncludeLiterals="true"
                          @bind-Value="@CellPhoneNumber"
                          Class="form-control" />
</span>

@* move this script to an actual script file instead of using this hack *@
<script suppress-error="BL9992">
    function collapseInputSelection(root) {
        setTimeout(function () {
            var input = root.querySelector("input");
            if (input) {
                input.setSelectionRange(0, 0);
            }
        }, 20);
    }
</script>

@code{
    string CellPhoneNumber { get; set; }

    ElementReference ParentElem { get; set; }
    async Task CollapseInputSelection()
    {
        await JsInterop.InvokeVoidAsync("collapseInputSelection", ParentElem);
    }
}

---

Unplanned
Last Updated: 16 Oct 2026 14:50 by ADMIN
Created by: const
Comments: 2
Category: DateTimePicker
Type: Bug Report
2

I want the user to only be able to select times between, for example, 11AM and 1PM. Setting Min and Max does not limit that, I can select any time:

Selected time: @selectedTime
<br />

<TelerikDateTimePicker Min="@Min" Max="@Max" @bind-Value="@selectedTime"
                       Format="dd MMM yyyy HH:mm" Width="250px"></TelerikDateTimePicker>

@code {
    private DateTime? selectedTime = DateTime.Now;
    public DateTime Min = new DateTime(2020, 6, 11, 10, 15, 0);
    public DateTime Max = new DateTime(2020, 6, 13, 12, 30, 45);
}
Unplanned
Last Updated: 16 Oct 2026 14:36 by ADMIN
I have a TreeList, bound to an ObservableCollection data source. When I try to add new children the component stays in Create mode even after I click on the Update button.
Unplanned
Last Updated: 16 Oct 2026 14:29 by ADMIN
Created by: chris
Comments: 2
Category: RadioGroup
Type: Bug Report
1

A RadioGroup inside a Grid EditorTemplate will fire OnBlur when the user clicks on it. This will close the edit cell and (usually) not apply the new value.

Here is a test page: https://blazorrepl.telerik.com/wvbmkMvd48rpMN4547

Unplanned
Last Updated: 16 Oct 2026 14:01 by ADMIN
Cannot remove the last series of a dynamically created chart
Unplanned
Last Updated: 16 Oct 2026 13:09 by ADMIN

The code below compiles and doesn't give any browser errors when run, but when you collapse a row, all data is collapsed and you can't expand it again.

If you change the line that generates the data to use a List instead of IEnumerable it will work as expected.

REPRODUCIBLE

<TelerikTreeList Data=Data
                 IdField="@nameof(Record.Id)"
                 ParentIdField="@nameof(Record.ParentId)"
                 Height="100%">
    <TreeListColumns>
        <TreeListCheckboxColumn CheckBoxOnlySelection="true" />
        <TreeListColumn Field="@nameof(Record.Text)" Title="" Expandable="true" />
        <TreeListColumn Field="@nameof(Record.Id)" Title="ID" />
        <TreeListColumn Field="@nameof(Record.ParentId)" Title="PARENT" />
    </TreeListColumns>
</TelerikTreeList>
@code {
    protected IEnumerable<Record> Data = new List<Record>();

    protected override void OnInitialized()
    {
        Data = Enumerable.Range(1, 10).Select(i => new Record(i));
    }

    public class Record
    {
        public Record(int i)
        {
            Id = i;
            if (i % 5 == 1)
                ParentId = null;
            else
                ParentId = (i - ((i - 1) % 5));
            Text = "Item " + i;
        }
        public long Id { get; set; }
        public long? ParentId { get; set; }
        public string Text { get; set; }
    }
} 

WORKAROUND

<TelerikTreeList Data=Data
                 IdField="@nameof(Record.Id)"
                 ParentIdField="@nameof(Record.ParentId)"
                 Height="100%">
    <TreeListColumns>
        <TreeListCheckboxColumn CheckBoxOnlySelection="true" />
        <TreeListColumn Field="@nameof(Record.Text)" Title="" Expandable="true" />
        <TreeListColumn Field="@nameof(Record.Id)" Title="ID" />
        <TreeListColumn Field="@nameof(Record.ParentId)" Title="PARENT" />
    </TreeListColumns>
</TelerikTreeList>
@code {
    protected List<Record> Data = new List<Record>();

    protected override void OnInitialized()
    {
        Data = Enumerable.Range(1, 10).Select(i => new Record(i)).ToList();
    }

    public class Record
    {
        public Record(int i)
        {
            Id = i;
            if (i % 5 == 1)
                ParentId = null;
            else
                ParentId = (i - ((i - 1) % 5));
            Text = "Item " + i;
        }
        public long Id { get; set; }
        public long? ParentId { get; set; }
        public string Text { get; set; }
    }
} 

 

Unplanned
Last Updated: 16 Oct 2026 12:55 by ADMIN

I am trying to look at the times 7pm - midnight.  But if I set the end time to midnight, I get an error that the end time has to be greater than the start time.  How do I set the timeline to show 7pm - midnight or 8pm - 2am?

I tried including the next date in the EndTime but the Scheduler does not take the date into consideration, it checks only the time portion.

Unplanned
Last Updated: 16 Oct 2026 08:28 by ADMIN

Entering dates in the Blazor spreadsheet act weird if you enter a 2 digit year. It seems to subtract a day when you remove focus from the cell.

Start by entering a date like 2/2/25:

Then hit enter or otherwise remove focus from the cell and this is what it changes it to. Notice it subtracts a day:

Then put focus back on the cell:

Now look at the editor at the top:

I note that when you enter a two digit year in Excel it defaults the century to 20 when you enter a year less than 30. It defaults a century of 19 when you enter a year >= 30. It appears that with the Telerik Blazor spreadsheet it always defaults the century to 19. You can make arguments on either side of that but the real issue here is that it subtracts a day when you enter a two digit year. It doesn't do that when you enter a 4 digit year.

The related thing that becomes an issue is when you export the spreadsheet to a byte array and evaluate the cell RawValue. When you enter a 4 digit year, you get a raw value that is a positive number and you can use FormatHelper.ConvertDoubleToDateTime to get the date value. When you enter a 2 digit year and get the raw value, it is a negative number, and when you call FormatHelper.ConvertDoubleToDateTime it returns null.

Can you please comment on the rhyme or reason the spreadsheet behaves this way? Or is this a bug(s)?

Thanks.

Unplanned
Last Updated: 16 Oct 2026 08:01 by Wes
Created by: Wes
Comments: 0
Category: PDFViewer
Type: Bug Report
5
When printing from the Blazor PDF Viewer it is not consistent in actually preparing it to print.  Sometimes it works and sometimes it's blank pages.  This is all on the same document.  I can usually get it to work by clicking print over and over and until it renders correctly.
Planned
Last Updated: 14 Oct 2026 13:57 by ADMIN
Scheduled for 2026 (Nov)
Created by: Sebastian
Comments: 4
Category: PDFViewer
Type: Bug Report
1
  • The PDF Viewer does not display the initial file if Zoom is set to FitToWidth or FitToPage. This is due to --scale-factor: NaN; --total-scale-factor: NaN; set on the PDF Viewer element.
  • If the PDF Viewer initially shows with no loaded file, setting Zoom to FitToWidth or FitToPage initially or after opening a file leads to infinity zoom due to --scale-factor: Infinity; --total-scale-factor: Infinity; set on the PDF Viewer element.

The only scenario that works is to set the initial Zoom to a numeric value and have an open file by default.

Planned
Last Updated: 13 Oct 2026 10:43 by ADMIN
Our "Level Access" accessibility scanning tool revealed that the RadioGroup component uses the aria-checked=true with input[type=radio] which could cause accessibility issues if conflicting.
Planned
Last Updated: 13 Oct 2026 10:43 by ADMIN

Bug report

Reproduction of the problem

(bug report only)
The label of the filter menu icon displays: “column filter menu settings”. In version 12.0.0 it included the name of the column field.

1. Run this example: https://blazorrepl.telerik.com/cKFaOPvO56rcaHqx16
2. Hover a filter icon in the Grid’s header with the mouse cursor.

Current behavior

(optional)
The label “column filter menu settings” appears.

Expected/desired behavior

The label text includes the column name, e.g., “Price column filter menu settings”.

Workaround:

https://blazorrepl.telerik.com/cUPYaPlO55EJNiKJ24

Environment

  • Kendo/Telerik version: 15.0.1
  • Browser: [all]
Unplanned
Last Updated: 12 Oct 2026 14:34 by AMF
Created by: AMF
Comments: 0
Category: ContextMenu
Type: Bug Report
1

The ContextMenu components triggers a page scroll up on first opening. The problem may be specific to WebAssembly apps. Here is a test page with an applied workaround:

https://blazorrepl.telerik.com/wglavwvy31XgaQIJ18

The important code in the above example is:

<TelerikContextMenu @ref="@ContextMenuRef" />

@code {
    private TelerikContextMenu<ContextMenuItem> ContextMenuRef { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender && ContextMenuRef is not null)
        {
            await Task.Delay(1);
            await ContextMenuRef.ShowAsync(1, 1);
            await ContextMenuRef.HideAsync();
        }
    }
}

 

Completed
Last Updated: 12 Oct 2026 10:25 by ADMIN

When I click on the CheckBox's label, "Select All," the dropdown closes. While if I click the TelerikCheckBox itself, it remains open.

===

TELERIK EDIT

Please use the built-in Select All functionality of the MultiSelect. It doesn't exhibit the described problem.

For other scenarios that require a checkbox in the HeaderTemplate, Possible workarounds include:

Completed
Last Updated: 12 Oct 2026 10:12 by ADMIN
Created by: NovaStor
Comments: 1
Category: TreeList
Type: Bug Report
1

I'm experiencing a flickering in the TreeList InCell Editing demo here: https://demos.telerik.com/blazor-ui/treelist/editing-incell

Steps to reproduce:

1. Click on "Mountain Bikes"

2. Click on "Road Bikes"

3. Click on "Touring Bikes"

It can actually be reproduced by clicking on any three editable cells.

Any ideas?

Thank you.

Completed
Last Updated: 12 Oct 2026 10:09 by ADMIN

Use a ToolBar with its ToolBarTemplateItem (with DropDownList inside of the template) in a separate component. Try to switch values in the DropDownList with the arrows of the keyboard. The value in the DropDownList does not change until you move away from it with a right arrow. This only happens when the template with the dropdown inside is in a separated component.

 

-------------------- ADMIN EDIT --------------------

The workaround for such a scenario is to export the DropDownList too onto a separated component and then call it in the ToolBarTemplateItem. See the attached sample project.

In Development
Last Updated: 12 Oct 2026 09:47 by ADMIN
Scheduled for 2026 (Nov)

Hello,

When a Grid is using multi column headers, and I add one more column in the OnBeforeExport event, this new column has no title in the exported file.

A possible workaround might be to use a column with zero Width and change the width in OnBeforeExport.

@using Telerik.Blazor.Common.Export.Excel
@using Telerik.Blazor.Components.Grid

<TelerikGrid TItem="@FlowRun"
             Pageable="true"
             OnRead="@GetData">

    <GridToolBar>
        <GridCommandButton Command="ExcelExport" Icon="file-excel">Export to Excel</GridCommandButton>
        <GridCommandButton Command="CsvExport" Icon="file-csv">Export to CSV</GridCommandButton>
        <label class="k-checkbox-label"><TelerikCheckBox @bind-Value="@ExportAllPages" />Export All Pages</label>
    </GridToolBar>

    <GridExport>
        <GridExcelExport FileName="telerik-grid-export" AllPages="@ExportAllPages" OnBeforeExport="@BeforeExcelExport" />
        <GridCsvExport FileName="telerik-grid-export" AllPages="@ExportAllPages" OnBeforeExport="@BeforeCsvExport" />
    </GridExport>

    <GridColumns>
        <GridColumn Field="@nameof(FlowRun.FileName)" Title="File Name" Width="300px" />
        <GridColumn Field="@nameof(FlowRun.Type)" Title="Type" Width="100px" />
        <GridColumn Field="@nameof(FlowRun.FileSize)" Title="File Size" Width="200px" />
        <GridColumn Title="Source">
            <Columns>
                <GridColumn Field="@(nameof(FlowRun.Source))" Title="MPID"/>
                <GridColumn Field="@(nameof(FlowRun.SourceFileProtocol))" Title="Type" />
            </Columns>
        </GridColumn>
        <GridColumn Field="@nameof(FlowRun.ErrorMessage)"
                    Title = "Error"
                    Width="0" />
    </GridColumns>
</TelerikGrid>

@code {
    bool ExportAllPages { get; set; }

    private async Task GetData(GridReadEventArgs args)
    {
        args.Data = Enumerable.Range(1, 10).Select(x => new FlowRun
            {
                FileName = $"File {x}",
                Type = $"Type {x}",
                FileSize = x * 2,
                Source = $"Source {x}",
                SourceFileProtocol = FileProtocol.CIX,
                ErrorMessage = $"Error {x}"
            }).ToList();

        args.Total = 100;
    }

    private void BeforeCsvExport(GridBeforeCsvExportEventArgs obj)
    {
        AddErrorMessageColumn(obj);
    }

    private void BeforeExcelExport(GridBeforeExcelExportEventArgs obj)
    {
        AddErrorMessageColumn(obj);
    }

    private void AddErrorMessageColumn(GridBeforeSpreadsheetExportEventArgs args)
    {
        args.Columns.Find(x => x.Field == nameof(FlowRun.ErrorMessage)).Width = "100px";

        //args.Columns.Add(new ExcelExportableColumn
        //{            
        //    Field = nameof(FlowRun.ErrorMessage),
        //    Title = "Error"
        //});
    }

    public class FlowRun
    {
        public string FileName { get; set; }
        public string Type { get; set; }
        public long? FileSize { get; set; }
        public string Source { get; set; }
        public FileProtocol SourceFileProtocol { get; set; }
        public string ErrorMessage { get; set; }
    }

    public enum FileProtocol
    {
        Unknown,
        PIX,
        CIX,
        SS
    }
}

Completed
Last Updated: 12 Oct 2026 09:18 by ADMIN

I am overriding the built-in Add command and setting an InsertedItem through the TreeList state. However, it looks like the the built-in validation is invoked twice and two validation Tooltips are displayed for the field.

 

Completed
Last Updated: 12 Oct 2026 09:17 by ADMIN
I have a project with a grid and a context menu.  When I right click on a grid cell, I create a contextual menu based on the name in the grid row.  Then when I run the await ContextMenuRef.ShowAsync(mouseEventArgs.ClientX, mouseEventArgs.ClientY); command, the menu is from the previous right click and previous row.  The actions performed based on the menu choice happen for the right row but the menu itself, it shows previous values.  I have included my mock project for your perusal.  Click on Invoices to get to the page with the problem.
Completed
Last Updated: 12 Oct 2026 09:16 by ADMIN

When you type something in the grid searchbox, there will be a X at the end to clear the box.

However, if you restore the grid from previously stored state like localstorage, and if the box has value, the X is not there.

Thanks!

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