Completed
Last Updated: 10 Jul 2026 13:25 by ADMIN
Created by: Niraj
Comments: 0
Category: PivotGrid
Type: Bug Report
1
The PivotGrid row and column filtering is case sensitive. This makes the algorithm inconsistent with the other filtering features in Telerik UI for Blazor.
Unplanned
Last Updated: 09 Jul 2026 15:04 by ADMIN
Scheduled for 2026 Q3 (Aug)

Description

Appointment editing does not work on Chrome for mobile (Android).

Steps To Reproduce

Run the following demo in the Chrome for mobile browser, on a mobile device with Android : https://demos.telerik.com/blazor-ui/scheduler/appointment-editing

  1. Attempt to edit an appointment by double tapping it

Actual Behavior

The popup editor does not show up.

Expected Behavior

The popup editor shows up.

Browser

Chrome

Last working version of Telerik UI for Blazor (if regression)

No response

Completed
Last Updated: 09 Jul 2026 14:51 by ADMIN
Release 2026 Q2

The PDF standard allows two ways to configure Acro fields and relate them to inputs (widget annotations):

  1. The field can be independent of the input widget. There can even be multiple inputs that point to the same field.
  2. The field and the widget can be represented by the same object in the PDF file.

Adobe Acrobat supports both options. Telerik PdfProcessing supports only the first option, which is more commonly used. The PDF Viewer supports only the second option. If the PDF Viewer loads a file with the first configuration, the component saves new field values in such a way that they can't be retrieved by PdfProcessing. Moreover, if the PDF file is opened locally, it looks like the new values are there, but when you click on a field, the original value shows. The new value behaves like a placeholder rather than a real value.

To Reproduce

  1. Open a file with Acro fields in the PDF Viewer with enabled form filling
  2. Edit the fields and save the file.
  3. Open the file with a desktop client like Adobe Acrobat Reader.
  4. Click on a textbox.
  5. Result - the old value shows. Instead, the new value should persist.
Completed
Last Updated: 09 Jul 2026 14:25 by ADMIN
Release 13.1.0
The parameters "Resizable" and "Reorderable" let you control whether tiles can be resized and reordered. These work when using the mouse, but once you turn on keyboard navigation via setting the parameter "Navigable" to "true", you are able to resize and reorder the tiles using "Ctrl"/"Shift" + "Arrow keys", regardless of the parameter values for "Resizable" and "Reorderable".
Completed
Last Updated: 09 Jul 2026 14:18 by ADMIN
Release 13.1.0

When you select a date in DropDownList with dates in it (List<DateTime>), the @bind-Value is shaving off the milliseconds.

 

===ADMIN EDIT===

In the meantime, as a workaround for displaying milliseconds correctly, you can bind the DropDownList to a model. This way, you can use the "Id" to retrieve the selected item and display its precise milliseconds. Below is an example I've prepared to demonstrate this approach:

Selected value: @myDdlData.ToList().Where(x => x.Id == selectedValueId).FirstOrDefault()?.MyValueField.ToString("MM/dd/yyyy HH:mm:ss.fff")
<br />

<TelerikDropDownList Data="@myDdlData" 
                     TextField="MyTextField" 
                     ValueField="Id" 
                     @bind-Value="selectedValueId">
</TelerikDropDownList>

@code {
    public class MyDdlModel
    {
        public int Id { get; set; }
        public DateTime MyValueField { get; set; }
        public string MyTextField => MyValueField.ToString("MM/dd/yyyy HH:mm:ss.fff"); // Display formatted DateTime
    }

    private int selectedValueId { get; set; } = 1;

    private IEnumerable<MyDdlModel> myDdlData = GenerateRandomDateTimes(20);

    private static IEnumerable<MyDdlModel> GenerateRandomDateTimes(int count)
    {
        Random random = new Random();
        DateTime startDate = DateTime.Now;

        return Enumerable.Range(1, count)
            .Select(x => new MyDdlModel
            {
                Id = x, // Unique integer Id
                MyValueField = startDate.AddDays(x)
                    .AddMinutes(random.Next(0, 60))
                    .AddSeconds(random.Next(0, 60))
                    .AddMilliseconds(random.Next(0, 1000))
            }).ToList();
    }
}

Unplanned
Last Updated: 09 Jul 2026 14:10 by ADMIN
Created by: Emma
Comments: 3
Category: Scheduler
Type: Bug Report
0

I have been having issues adding the month view to a Telerik Blazor scheduler component, when there is grouping. It gives a null reference error any time I try to switch to the month view. I also tried it using the available demo for grouping in Telerik REPL, the only difference I found between my code and the demo was that I had used the ItemsPerSlot parameter.  I added this to the demo, and was able to reproduce the error I was seeing, and I have attached the console output from the REPL demo. I believe there is either a bug with the ItemsPerSlot being used in conjunction with grouping on a scheduler component, or some instruction missing from how to set it up properly to prevent this null reference issue. 

Changed code:

<SchedulerMonthView ItemsPerSlot="5"></SchedulerMonthView>

Demo used:

Blazor Scheduler (Event Calendar) Demos - Grouping | Telerik UI for Blazor

 


Completed
Last Updated: 09 Jul 2026 14:07 by ADMIN
Release 2026 Q2
Created by: Robert
Comments: 3
Category: Grid
Type: Bug Report
0
A virtual Grid does not handle well dynamic RowHeight changes. The virtual scrollbar is not refreshed and scrolling breaks.
Completed
Last Updated: 09 Jul 2026 14:02 by ADMIN
Release 2026 Q3 (Aug)
  • If you select a row and then unselect that row (SelectedItems is empty), and hit the incorrectly enabled delete button, it removes a row that has not been selected. When there is no selected row, the delete tool should be disabled.
  • If you use multiple selection, the delete tool will delete the last row, which is unexpected. It should delete all selected rows.

Workaround:

<TelerikGrid Data="@GridData"
             SelectionMode="@GridSelectionMode.Multiple"
             SelectedItems="@SelectedItems"
             SelectedItemsChanged="@( (IEnumerable<Employee> newSelected) => OnSelectedItemsChanged(newSelected) )"
             Height="300px">
    <GridToolBarTemplate>
        <TelerikButton Enabled="@(SelectedItems.Any())" OnClick="@DeleteSelectedEmployees">Delete</TelerikButton>
    </GridToolBarTemplate>
    <GridColumns>
        <GridCheckboxColumn SelectAll="true" />
        <GridColumn Field="Name" Title="Name" />
        <GridColumn Field="Team" Title="Team" />
    </GridColumns>
</TelerikGrid>

@code {
    private List<Employee> GridData { get; set; } = Enumerable.Range(1, 10).Select(i => new Employee
    {
        EmployeeId = i,
        Name = $"Employee {i}",
        Team = $"Team {i % 3}"
    }).ToList();

    private List<Employee> SelectedItems { get; set; } = new();

    private void OnSelectedItemsChanged(IEnumerable<Employee> items)
    {
        SelectedItems = items.ToList();
    }

    private void DeleteSelectedEmployees()
    {
        if (SelectedItems.Any())
        {
            GridData = GridData.Except(SelectedItems).ToList();
            SelectedItems.Clear();
        }
    }

    public class Employee
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public string Team { get; set; }
        public override bool Equals(object obj) => obj is Employee e && e.EmployeeId == EmployeeId;
        public override int GetHashCode() => EmployeeId.GetHashCode();
    }
}

Completed
Last Updated: 08 Jul 2026 14:38 by ADMIN
Release 2026 Q3 (Aug)

Telerik input components inside EditorTemplate render the whole grid on each keystroke

 

<AdminEdit>

As a workaround, you can use the standard Input components provided by the framework together with a CSS class that would visually make them like the Telerik Input Components. An example for the TextArea:

<InputTextArea class="k-textarea" @bind-Value="@myValue"></InputTextArea>

</AdminEdit>

Completed
Last Updated: 08 Jul 2026 07:43 by ADMIN
Created by: Hieu
Comments: 0
Category: AutoComplete
Type: Bug Report
8

The AutoComplete component does not update the category grouping header, even when the data within that group has been removed. As a result, the outdated group header remains visible until you scroll down to another group, at which point the first group header refreshes and disappears as expected.

Repro: REPL link.

Completed
Last Updated: 07 Jul 2026 15:01 by ADMIN
Created by: Marcin
Comments: 0
Category: Grid
Type: Bug Report
1

Bug report

Reproduction of the problem

(bug report only)
Regression introduced in 9.0.0.

1. Run the code posted below and export the Grid.
2. Open the exported Excel file.

<TelerikGrid Data=@GridData
             Pageable="true" Sortable="true" Resizable="true" Reorderable="true"
             ShowColumnMenu="true" FilterMode="@GridFilterMode.FilterMenu"
             Width="800px" Height="400px">
    <GridToolBar>
        <GridToolBarExcelExportTool>
            Export to Excel
        </GridToolBarExcelExportTool>
    </GridToolBar>
    <GridExport>
        <GridExcelExport FileName="telerik-grid-export" AllPages="false" />
    </GridExport>
    <GridColumns>
        <GridColumn Title="Personal Information">
            <Columns>
                <GridColumn Field=@nameof(Customer.FirstName) Title="First Name" Width="100px" />
                <GridColumn Field=@nameof(Customer.LastName) Title="Last Name" Width="100px" />
            </Columns>
        </GridColumn>
        <GridColumn Title="Company">
            <Columns>
                <GridColumn Field=@nameof(Customer.CompanyName) Title="Name" />
                <GridColumn Field=@nameof(Customer.HasCompanyContract) Title="Has Contract" Width="120px" />
            </Columns>
        </GridColumn>
        <GridColumn Title="Contact Details">
            <Columns>
                <GridColumn Field="@nameof(Customer.Email)" Title="Email"></GridColumn>
                <GridColumn Field="@nameof(Customer.Phone)" Title="Phone"></GridColumn>
                <GridColumn Field="@nameof(Customer.City)" Title="City"></GridColumn>
            </Columns>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

@code {
    public List<Customer> GridData { get; set; }

    public class Customer
    {
        public int Id { get; set; }
        public string PasswordHash { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string CompanyName { get; set; }
        public bool HasCompanyContract { get; set; }
        public string Email { get; set; }
        public string Phone { get; set; }
        public string City { get; set; }
    }

    // generation of dummy data
    protected override void OnInitialized()
    {
        GridData = GenerateData();
    }

    List<Customer> GenerateData()
    {
        var data = new List<Customer>();

        string[] fNames = new string[] { "Nancy", "John", "Orlando", "Jane", "Bob", "Juan" };
        string[] lNames = new string[] { "Harris", "Gates", "Smith", "Caprio", "Gash", "Gee" };
        string[] cNames = new string[] { "Acme", "Northwind", "Contoso" };
        string[] cities = new string[] { "Denver", "New York", "LA", "London", "Paris", "Helsinki", "Moscow", "Sofia" };
        Random rnd = new Random();

        for (int i = 0; i < 150; i++)
        {
            string fName = fNames[rnd.Next(0, fNames.Length)];
            string lName = lNames[rnd.Next(0, lNames.Length)];
            string cName = cNames[rnd.Next(0, cNames.Length)];
            data.Add(new Customer
            {
                Id = i,
                PasswordHash = "not shown",
                FirstName = fName,
                LastName = lName,
                CompanyName = cName,
                HasCompanyContract = i % 3 == 0,
                Email = $"{fName}.{lName}@{cName}.com",
                Phone = $"{rnd.Next(100, 999)}-555-{rnd.Next(100, 999)}",
                City = cities[rnd.Next(0, cities.Length)]
            });
        }

        return data;
    }
}

Current behavior

(optional)
The “Personal Information”, “Company”, “Contact Details” headers are not exported.

Expected/desired behavior

The multi-column headers are exported.

Environment

  • Kendo/Telerik version: 14.0.0
  • Browser: [all ]
Unplanned
Last Updated: 07 Jul 2026 10:22 by Domingos Portela

The Grid resets and disables the adaptive mode for a column menu if the column has been hidden. The component also uses the previous adaptive mode that is no longer correct if the browser window is resized.

Steps to reproduce:

  • Shrink the browser width. Hide a column, show it back and then show its column menu.
  • Start from a wide browser. Show a column menu. Shrink the browser. Show the same column menu.
  • Start from a narrow browser. Show a column menu. Expand the browser. Show the same column menu.

Test page:

<TelerikGrid Data="@GridData"
             AdaptiveMode="@AdaptiveMode.Auto"
             FilterMode="GridFilterMode.FilterMenu"
             ShowColumnMenu="true">
    <GridColumns>
        <GridColumn Field="@nameof(Product.Name)" />
        <GridColumn Field="@nameof(Product.Group)" />
        <GridColumn Field="@nameof(Product.Price)" DisplayFormat="{0:c2}" />
        <GridColumn Field="@nameof(Product.Quantity)" DisplayFormat="{0:n0}" />
        <GridColumn Field="@nameof(Product.Released)" DisplayFormat="{0:d}" />
        <GridColumn Field="@nameof(Product.Discontinued)" />
    </GridColumns>
</TelerikGrid>

@code {
    private List<Product> GridData { get; set; } = new();

    protected override void OnInitialized()
    {
        var rnd = Random.Shared;

        for (int i = 1; i <= 3; i++)
        {
            GridData.Add(new Product()
            {
                Id = i,
                Name = $"Name {i} {(char)rnd.Next(65, 91)}{(char)rnd.Next(65, 91)}",
                Group = $"Group {i % 3 + 1}",
                Price = rnd.Next(1, 100) * 1.23m,
                Quantity = rnd.Next(0, 10000),
                Released = DateTime.Today.AddDays(-rnd.Next(60, 1000)),
                Discontinued = i % 4 == 0
            });
        }
    }

    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
        public string Group { get; set; } = string.Empty;
        public decimal Price { get; set; }
        public int Quantity { get; set; }
        public DateTime Released { get; set; }
        public bool Discontinued { get; set; }
    }
}

Unplanned
Last Updated: 07 Jul 2026 07:17 by Sadik

Customers report inconsistent in-cell editing behavior with DatePicker columns in the Grid.

  • Case 1: click a date cell to enter edit mode, then click outside the Grid — edit mode terminates.
  • Case 2: click a date cell to enter edit mode, open the DatePicker popup, then click outside the Grid — the popup closes but the cell remains stuck in edit mode until pressing Esc or clicking another cell.

Here is a REPL test page that reproduces the issue (first date column) and provides a workaround (second date column):

https://blazorrepl.telerik.com/QAErkrEh090ykIxR16

The workaround relies on Grid EditorTemplate, the DatePicker OnClose event, and programmatic Grid edit mode management. The relevant code is:

@using System.ComponentModel.DataAnnotations

<TelerikGrid @ref="@GridRef"
             Data="@GridData"
             EditMode="@GridEditMode.Incell"
             OnUpdate="@OnGridUpdate"
             OnCreate="@OnGridCreate">
    <GridToolBarTemplate>
        <GridCommandButton Command="Add">Add Item</GridCommandButton>
    </GridToolBarTemplate>
    <GridColumns>
        <GridColumn Field="@nameof(Product.Name)" />
        <GridColumn Field="@nameof(Product.StartDate)" Title="BUG" DisplayFormat="{0:d}" />
        <GridColumn Field="@nameof(Product.EndDate)" Title="WORKAROUND" DisplayFormat="{0:d}">
            <EditorTemplate>
                @{ var editItem = (Product)context; }
                <TelerikDatePicker Value="editItem.EndDate"
                                   ValueChanged="@((DateTime? newValue) => OnGridDatePickerValueChanged(newValue, editItem))"
                                   ValueExpression="@( () => editItem.EndDate )"
                                   OnClose="@(async () => await OnGridDatePickerClose(editItem))" />
            </EditorTemplate>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

@code {
    #nullable enable

    private TelerikGrid<Product>? GridRef;
    private List<Product> GridData { get; set; } = new();

    private int LastId { get; set; }

    private DateTime LastDatePickerValueChanged { get; set; } = DateTime.Now;

    private void OnGridDatePickerValueChanged(DateTime? newValue, Product editItem)
    {
        editItem.EndDate = newValue;
        LastDatePickerValueChanged = DateTime.Now;
    }

    private async Task OnGridDatePickerClose(Product editItem)
    {
        if (DateTime.Now - LastDatePickerValueChanged > TimeSpan.FromMilliseconds(500))
        {
            GridState<Product> gridState = GridRef!.GetState();

            if (gridState.EditItem is not null && gridState.EditItem.Id == editItem.Id)
            {
                // Uncomment to perform an item update instead of cancel
                // OnGridUpdate(new GridCommandEventArgs { Item = editItem });

                gridState.OriginalEditItem = null!;
                gridState.EditItem = null!;

                await GridRef.SetStateAsync(gridState);
            }
        }
    }

    private void OnGridCreate(GridCommandEventArgs args)
    {
        var createdItem = (Product)args.Item;

        createdItem.Id = ++LastId;

        GridData.Insert(0, createdItem);
    }

    private void OnGridUpdate(GridCommandEventArgs args)
    {
        var updatedItem = (Product)args.Item;
        var originalItemIndex = GridData.FindIndex(i => i.Id == updatedItem.Id);

        if (originalItemIndex != -1)
        {
            GridData[originalItemIndex] = updatedItem;
        }
    }

    protected override void OnInitialized()
    {
        for (int i = 1; i <= 5; i++)
        {
            GridData.Add(new Product()
            {
                Id = ++LastId,
                Name = $"Product {LastId}",
                Price = Random.Shared.Next(0, 100) * 1.23m,
                Quantity = Random.Shared.Next(0, 1000),
                StartDate = DateTime.Today.AddDays(-Random.Shared.Next(60, 1000)),
                EndDate = DateTime.Today.AddDays(Random.Shared.Next(1, 60)),
                IsActive = LastId % 4 > 0
            });
        }
    }

    public class Product
    {
        public int Id { get; set; }
        [Required]
        public string Name { get; set; } = string.Empty;
        public decimal Price { get; set; }
        public int Quantity { get; set; }
        public DateTime? StartDate { get; set; }
        public DateTime? EndDate { get; set; }
        public bool IsActive { get; set; }
    }
}

Completed
Last Updated: 06 Jul 2026 13:53 by ADMIN
Release 2026 Q1 (Feb)
Created by: Stas
Comments: 0
Category: Spreadsheet
Type: Bug Report
2
The Spreadsheet component throws a JS error (undefined is not an object (evaluating 't.forEach')) when exporting an Excel file that contains rows without any cells.
Completed
Last Updated: 03 Jul 2026 06:07 by Jan
Release 2026 14.1.0 (Jul)
Created by: David Rhodes
Comments: 2
Category: TabStrip
Type: Bug Report
4

The TabStrip ActiveTabIdChanged event fires when the user navigates to another page.

The workaround is to detect app navigation and prevent the business logic execution. The example below is for the general case. If the app navigates programmatically with NavigationManager.NavigateTo(), you can set the IsNavigating flag immediately before that.

@implements IDisposable
@inject NavigationManager NavManager

<TelerikTabStrip ActiveTabId="@ActiveTabId"
                 ActiveTabIdChanged="@TabStripActiveTabIdChanged">
    @for (int i = 1; i <= TabCount; i++)
    {
        int tabIndex = i;

        <TabStripTab @key="@tabIndex" Title="@($"Tab {tabIndex}")" Id="@($"tab{tabIndex}")">
            <h2>Tab @tabIndex</h2>
        </TabStripTab>
    }
</TelerikTabStrip>

@code {
    private string ActiveTabId { get; set; } = "tab1";

    private bool IsNavigating { get; set; }

    private const int TabCount = 3;
    

    private async Task TabStripActiveTabIdChanged(string newActiveTabId)
    {
        if (IsNavigating)
        {
            return;
        }

        ActiveTabId = newActiveTabId;
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            locationChangingRegistration = NavManager.RegisterLocationChangingHandler(OnLocationChanging);
        }
    }

    private IDisposable? locationChangingRegistration;

    private ValueTask OnLocationChanging(LocationChangingContext context)
    {
        IsNavigating = true;

        return ValueTask.CompletedTask;
    }

    public void Dispose() => locationChangingRegistration?.Dispose();
}

Unplanned
Last Updated: 02 Jul 2026 13:42 by ADMIN
Created by: Miroslav
Comments: 0
Category: Tooltip
Type: Bug Report
4

If the element of the tooltip is on top of the screen (almost outside of the viewport), hovering the remaining part of the element makes the tooltip create a flashing effect.

Please watch the attached video. 

Unplanned
Last Updated: 02 Jul 2026 13:42 by ADMIN
Created by: ManojKumar
Comments: 6
Category: Tooltip
Type: Bug Report
4

When I place a tooltip on drawer item, it just flickers randomly

[video-to-gif output image]

https://blazorrepl.telerik.com/wQbbmbGb05hzznPh45

 
Unplanned
Last Updated: 30 Jun 2026 10:52 by ADMIN
Focus is lost after selecting an item from the dropdown in Firefox, but only when using the mouse. When selecting an item via the keyboard, the focus remains on the input element as expected.
Completed
Last Updated: 30 Jun 2026 08:49 by ADMIN
Release 2026 14.1.0 (Jul)
Created by: Alexander
Comments: 0
Category: FileManager
Type: Bug Report
1

The FileManager crashes with a null reference exception when the selected file is deleted while the preview pane is open.

https://demos.telerik.com/blazor-ui/filemanager/overview

Error: System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Object.GetType()
   at Telerik.Blazor.Components.TelerikFileManager`1.ConvertToFileEntry(Object dataItem)
   at Telerik.Blazor.Components.TelerikFileManager`1.GetSelectedEntryForDetails()
   at Telerik.Blazor.Components.TelerikFileManager`1.<BuildRenderTree>b__397_15(RenderTreeBuilder __builder3)
   at Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder.AddContent(Int32 sequence, RenderFragment fragment)
   at Telerik.Blazor.Components.TelerikSplitter.BuildRenderTree(RenderTreeBuilder __builder)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException)

Completed
Last Updated: 29 Jun 2026 07:35 by ADMIN

Reproduction with Data parameter

https://blazorrepl.telerik.com/GJYPlrEW485dZtjX55

Reproduction with OnRead

I made a Blazor REPL reproduction: https://blazorrepl.telerik.com/mcuCGpYr4223mhWY49. Run and observe the person label is overlapping the dropdown.

How to reproduce:

  1. Get code from the Remote Data Example.
  2. Surround the ComboBox with a TelerikFloatingLabel, it will then look like this:
    <TelerikFloatingLabel Text="Person">
    <TelerikComboBox 
                    TItem="@Person" TValue="@int"
                     ScrollMode="@DropDownScrollMode.Virtual"
                     OnRead="@GetRemoteData"
                     ValueMapper="@GetModelFromValue"
                     ItemHeight="30"
                     PageSize="20"
                     TextField="@nameof(Person.Name)"
                     ValueField="@nameof(Person.Id)"
                     @bind-Value="@SelectedValue"
                     Filterable="true" FilterOperator="@StringFilterOperator.Contains">
        <ComboBoxSettings>
            <ComboBoxPopupSettings Height="200px" />
        </ComboBoxSettings>    
    </TelerikComboBox>
    </TelerikFloatingLabel>
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