Bug report

When using the Kendo MultiSelect TagHelper and binding it to a model property, the selected values are not populated.

Reproduction of the problem

Create the MultiSelect and bind it to a property of the view model:

@model API.Models.IndexViewModel

<kendo-multiselect for="SelectedCategoriesTagHelper"
                   bind-to="@Model.Categories"
                   datatextfield="Text"
                   datavaluefield="Value"
></kendo-multiselect> 

Expected/desired behavior

The MultiSelect TagHelper should correctly display the selected values when bound to a model property.

TicketID:

1682678

Environment

• Browser: [all]

### Bug report

When adding a <select> element as a custom tool in the Editor, the dropdown does not open.

### Reproduction of the problem

1) Run the Dojo sample and try to open the dropdown in the toolbar:

https://dojo.telerik.com/VVPUopDw

The same example work as expected with version 2023.1.117.

2) When using version 2024.4.1112, if you remove the "ref-toolbar-tool" attribute from the <div class='k-toolbar-item'> element, the dropdown opens as expected.

### Expected/desired behavior

The <select> element must function correctly when added as a custom tool in the toolbar.

### Workaround

Handle the "click" event of the select and prevent the event bubbling:

<script>
    $(function () {
        const selectElements = $('select[id^="symbolSelect_"]');
        $(selectElements).each(function (index) {
            this.addEventListener("click", clickHandlerSymbolSelect);
        });
    });

    function clickHandlerSymbolSelect(e) {
        e.stopPropagation(); //Prevent event bubbling, so Kendo cannot swallow or cancel the event.
        const sendingElement = e.target;
        sendingElement.showPicker();
        return true;
    }
</script>

### Environment

* **Kendo UI version: 2025.1.227
* **jQuery version: 3.7.1
* **Browser: [all]

### Bug report

When an Editor component in inline mode is set as an editor in an InCell editable Grid, the Grid cell does not enter edit mode on "click". The issue occurs since version 2023.1.314.

### Reproduction of the problem

1) Create an InCell editable Grid.

2) Set an Editor component in inline mode as an editor to a specified Grid column.

3) Try to edit the cell.

4) The cell flashes and does not enter edit mode.

A Dojo sample for reporduction: https://dojo.telerik.com/zQUvDQEq (check out the "ProductName" column)

### Expected/desired behavior

The Grid column that uses Editor component in inline mode must be editable.

### Environment

* **Kendo UI version: since 2023.1.314
* **jQuery version: 3.4.1
* **Browser: [all]

Bug report

The Thumbnail() option of the Editor's ImageBrowser configuration does not provide UrlHandler() option, which is available for the Image() option.
Referenced in this commit

Reproduction of the problem

1. Define an Editor and enable the ImageBrowser feature:
   Open this REPL example

Expected/desired behavior

The UrlHandler() function must be available to set the URL that serves the thumbnail using a JavaScript handler.

TicketID:

1682129

Environment

• **Telerik UI for ASP.NET Core version: 2025.1.227
• **Browser: [all]

### Bug report

When loading an editor through a partial View using EditorTemplateView(await Html.PartialAsync("PartialViewName")), the following error occurs:

The 'await' operator can only be used within an async lambda expression. Consider marking this lambda expression with the 'async' modifier.

### Reproduction of the problem

@(Html.Kendo().Form<UserViewModel>()
     .Name("myForm")
     .Items(items =>
     {
         items.Add().Field(f => f.Username).EditorTemplateView(await Html.PartialAsync("PartialViewName"));
      })
)

### Expected/desired behavior

The EditorTemplateView() must accept Html.PartialAsync("PartialViewName").

### Environment

* **Telerik UI for ASP.NET Core version: 2024.4.1112
* **Browser: [all]

### Bug report

The File() option of the Editor's FileBrowser configuration does not provide UrlHandler() option, which is available for the ImageBrowser.

### Reproduction of the problem

1) Define an Editor and enable the FileBrowser feature:

@(Html.Kendo().Editor()
    .Name("Description")
    .Tools(tools => tools
        .Clear()
        .InsertFile()
    )
    .FileBrowser(fileBrowser => fileBrowser
        .File("GetFile", "FileBrowser", new { path = "{0}" })
        .Read("Read", "FileBrowser")
        .Create("Create", "FileBrowser")
        .Destroy("Destroy", "FileBrowser")
        .Upload("Upload", "FileBrowser")
        )
)

2) The File() option sets URL responsible for serving the original file. Try to set it by using a JavaScript handler.

3) The File(x => x.UrlHandler("setURLHandler")) configuration is not available.

### Expected/desired behavior

The UrlHandler() function must be available to set the URL that serves the file using a JavaScript handler.

### Environment

* **Telerik UI for ASP.NET Core version: 2025.1.211
* **Browser: [all]

I am seeing that once a grid checkboxlist column filter exceeds about 1000 items the wait time appears to increase non-linearly (performance is worse than linear.)  For example, with 3,000 items the page freezes for about 30 seconds.  The data is fetched in under 50 milliseconds, so the vast majority of this time appears to be processing by Kendo.

Please see the attached for my configuration.

1. Installs both extensions ASP.NET Core and MVC without the latest MVC and ASP.Net Core product versions
2. Create an ASP.NET Core project with an older version
3. An Update Available Notification appears for ASP.Net Core
4. Click on the "Update Now" button
5. The Upgrade project wizard is launched
6. Click on "Next" button, then the following error appears:
   
   

### Bug report

When loading a PDF file using the PDFViewer configured for DPL processing, the file content is loaded partially.

### Reproduction of the problem

1) Open the DPL Processing Demo: https://demos.telerik.com/aspnet-core/pdfviewer/dpl-processing

2) The file content is not loaded as expected.

The issue started to occur in version 2025.1.211. When comparing the responses of the "pdfviewer/getinitialpdf?pageNumber=1" request, the response when using the previous version (2024.4.1112) is longer than that of version 2025.1.211.

### Expected/desired behavior

The content of the loaded PDF file must be complete.

### Environment

* **Telerik UI for ASP.NET Core version 2025.1.211
* **Browser: [all]

Bug report

Reproduction of the problem

Dojo example: https://dojo.telerik.com/eRazIrIB

1. Scroll the Grid

Current behavior

The data is requested, but it is not displayed in the Grid.

Expected/desired behavior

The data is displayed, regardless of the type of loader used.

Environment

• Kendo UI version: 2022.3.913
• jQuery version: x.y
• Browser: [all ]

### Bug report

When deferring the component scripts to a file and a specified item of a Form HtmlHelper has a defined editor through the Editor() configuration, a client-side error is thrown:

"Uncaught Error: Syntax error, unrecognized expression: #"

### Reproduction of the problem

1) Enable the global deferred initialization.

2) Define a Form HtmlHelper with a ComboBox editor for one of its items:

@model FormViewModel

@(Html.Kendo().Form<FormViewModel>()
    .Name("form")
    .HtmlAttributes(new { action = @Url.Action("SubmitData", "Home"), method = "POST" })
    .FormData(Model)
    .Items(items =>
    {
        items.Add()
            .Field(f => f.Username)
            .Label(l => l.Text("Username:"));

        items.Add()
        .Field(f => f.City)
        .Label(l => l.Text("City"))
        .Editor(editor => editor
          .ComboBox()
          .DataTextField("Text")
          .DataValueField("Value")
          .BindTo(new List<SelectListItem>()
          {
            new SelectListItem() { Text = "City A", Value = "1" },
            new SelectListItem() { Text = "City B", Value = "2" },
            new SelectListItem() { Text = "City C", Value = "3" }
          })
        );
    })
)
@(Html.Kendo().DeferredScriptFile())

3) When the page with the Form is loaded, open the browser console and examine the error.  Review the content of the loaded kendo-deferred-scripts-xxxxx.js file - the ComboBox initialization script is included after the Form initialization script. Attached you can find screenshots.

When using the TagHelper version of the Form, the ComboBox initialization script is included in the kendo-deferred-scripts-xxxxx.js file before the initialization script of the Form with a unique generated "id" for example "3451ce77-2736-437f-9584-f5a5255902c2". In this case, no client-side errors occur.

### Expected/desired behavior

When deferring the component scripts to a file, the Form with specified editors must be initialized as expected without client-side errors.

### Workaround

Use the TagHelper version of the Form or define the editor by using the EditorTemplateView() option:

        items.Add()
        .Field(f => f.City)
        .Label(l => l.Text("City"))
        .EditorTemplateView(Html.Partial("ComboEditor"));

// ~/Views/Shared/ComboEditor.cshtml

@model FormViewModel

@(Html.Kendo().ComboBoxFor(m => m.City)
.DataTextField("Text")
.DataValueField("Value")
.BindTo(new List<SelectListItem>() {
	new SelectListItem() { Text = "City A", Value = "1" },
	new SelectListItem() { Text = "City B", Value = "2" },
	new SelectListItem() { Text = "City C", Value = "3" }
})
)

### Environment

* **Telerik UI for ASP.NET Core version: 2024.4.1112
* **Browser: [ all ]

Bug report

When enabling Editing for the Grid or TreeList a "No License" overlay is displayed in the following scenarios:

Reproduction of the problem

• Grid: overlay is displayed on load

@(Html.Kendo().Grid<TelerikMvcApp13.Models.OrderViewModel>()
    .Name("grid")
    .Columns(columns =>
    {
        columns.Bound(p => p.OrderID).Filterable(false);
        columns.Bound(p => p.Freight);
        columns.Bound(p => p.OrderDate).Format("{0:MM/dd/yyyy}");
        columns.Bound(p => p.ShipName);
        columns.Bound(p => p.ShipCity);
        columns.Command(c => c.Edit());
    })
    .Editable(e=>e.Mode(GridEditMode.PopUp))
    .Pageable()
    .Sortable()
    .Scrollable()
    .Filterable()
    .DataSource(dataSource => dataSource
        .Ajax()
        .PageSize(20)
        .Model(m=>m.Id(o=>o.OrderID))
        .Read(read => read.Action("Orders_Read", "Grid"))
        .Update(read => read.Action("Orders_Update", "Grid"))
        .Create(read => read.Action("Orders_Create", "Grid"))
        .Destroy(read => read.Action("Orders_Destroy", "Grid"))
    )
)

• TreeList: initially there is no overlay. Clicking on "Edit" button shows overlay and "No License" popup.

@(Html.Kendo().TreeList<Kendo.Mvc.Examples.Models.TreeList.EmployeeDirectoryModelPopUp>()
    .Name("treelist")
    .Toolbar(toolbar => toolbar.Create())
    .Columns(columns =>
    {
        columns.Add().Field(e => e.FirstName).Width(220).Title("First Name");
        columns.Add().Field(e => e.LastName).Width(100).Title("Last Name");
        columns.Add().Field(e => e.Position);
        columns.Add().Field(e => e.HireDate).Format("{0:MMMM d, yyyy}");
        columns.Add().Field(e => e.Phone).Width(200);
        columns.Add().Field(e => e.Extension).Width(140).Title("Ext").Format("{0:#}");
        columns.Add().Width(300).Command(c =>
        {
            c.CreateChild().Text("Add child");
            c.Edit();
            c.Destroy();
        });
    })
    .Editable(e => e.Mode("popup"))
    .DataSource(dataSource => dataSource
        .Create(create => create.Action("Create", "EmployeeDirectory"))
        .Read(read => read.Action("All", "EmployeeDirectory"))
        .Update(update => update.Action("Update", "EmployeeDirectory"))
        .Destroy(delete => delete.Action("Destroy", "EmployeeDirectory"))
        .Model(m =>
        {
            m.Id(f => f.EmployeeId);
            m.ParentId(f => f.ReportsTo);
            m.Expanded(true);
            m.Field(f => f.FirstName);
            m.Field(f => f.LastName);
            m.Field(f => f.ReportsTo);
            m.Field(f => f.HireDate);
            m.Field(f => f.Extension).DefaultValue(0);
            m.Field(f => f.Position);
        })
    )
    .Height(540)
)

Expected/desired behavior

No overlay and popup should be displayed in case of valid license.

TicketID:

(optional)
Provide the TicketID, where the bug report initiated.

Environment

• Kendo UI version: 2025.1.211

### Bug report

When opening the filter menu of a specified column through the classic ColumnMenu, the filter container is displayed with scrollbars when the dropdown of the filter operator is opened.

### Reproduction of the problem

1) Define a Grid and enable its classic ColumnMenu.

2) Open the filter menu of a specified column and then open the dropdown to select a filter operator.

3) The filter container has scrollbars. The "k-menu-popup" element has "overflow: auto";

Use the following demo to test the case and select the "classic" type for the ColumnMenu: https://demos.telerik.com/kendo-ui/grid/column-menu

The issue does not appear when using version 2024.4.1112.

### Expected/desired behavior

The filter menu container must not change its appearance when the dropdown opens.

### Workaround:

<style>
.k-menu-popup {
    overflow: visible !important;
}
</style>

Bug report

The column format applied through the .Format() option is ignored, if the column is bound to a nullable DateOnly field.

Reproduction of the problem

1. Declare a nullable DateOnly field in the view model:

public DateOnly? PaymentDate { get; set; }

2. Bind a column to the field and set its format:

columns.Bound(p => p.PaymentDate).Title("Date").Format("{0:MM/dd/yyyy}").Width(160);

Current behavior

The specified format is ignored, e.g., the Grid shows 2025-01-21, instead of 01/21/2025

Expected/desired behavior

The specified column format is applied.

Environment

• Kendo UI version: 2024.4.1112
• Browser: [all ]

### Bug report

When dragging and dropping a file into a specified FileManager folder, the Upload request triggers twice.

### Reproduction of the problem

1. Open the FileManager Demo: https://demos.telerik.com/kendo-ui/filemanager/index

2. Open the browser's Network tab.

3. Drag and drop a file into the FileManager.

4. Two Upload requests are triggered one after another.

### Expected/desired behavior

When uploading a single file with drag & drop, a single Upload request must trigger. When using the default upload button to upload a file, a single request triggers as expected.

### Environment

* **Kendo UI version: 2024.4.1112
* **jQuery version: 3.7.1
* **Browser: [all]

In this screenshot, End Date and Subm Is Open are "nested" properties, and Prod Date and Is LatestVersion are *not* nested.  The row filter functionality is not displaying the correct row filter widget.

Here's a data sample:

### Bug report

When the Grid filter menu is customized with a DropDownList, the initial option defined by using the "index" property is not set.

### Reproduction of the problem

A Dojo sample for reproduction: https://dojo.telerik.com/OmeXUfaF

### Expected/desired behavior

The DropDownList should be initialized with an initially selected option.

### Environment

* **Kendo UI version: 2022.1.119
* **jQuery version: 1.12.4
* **Browser: [all]

Bug report

Reproduction of the problem

1. Open the following dojo.
2. Open the column menu.
3. Try to remove all columns through the checkboxes.

Current behavior

The last checkbox selection is not disabled and allows all the columns to be removed if the menu options for the command column are explicitly set to false:

Expected/desired behavior

The last checkbox selection should be disabled without allowing all the columns to be removed if the menu options for the command column are explicitly set to false:

The following dojo depicts the aforementioned behavior.

Environment

• Kendo UI version: 2023.3.1010
• jQuery version: x.y
• Browser: [all]

Bug report

MultiSelect configured for server-filtering="true" sends an empty request on focusout

     <kendo-multiselect for="SelectedOrderIds" style="width:100%"
                       placeholder="Select addresses..."
                       datatextfield="ShipName"
                       datavaluefield="OrderID"
                       filter="FilterType.Contains"
                       value="Model.SelectedOrders.Select(x=>x.OrderID)">
        <datasource type="DataSourceTagHelperType.Ajax" server-filtering="true">
            <transport>
                <read url="@Url.Page("Index", "Read")" data="forgeryToken" />
            </transport>
            <schema data="Data">
                <model id="OrderID">
                    <fields>
                        <field name="ShipName" type="string"></field>
                    </fields>
                </model>              
            </schema>
        </datasource>
    </kendo-multiselect>

Reproduction of the problem

TelerikAspNetCoreApp197.zip

1. Run the attached application
2. Enter 34, for example, and select the returned item
3. Click outside of the MultiSelect

Current behavior

An empty request is sent, fetching all data.

Expected/desired behavior

A request should not be sent.

Environment

• Kendo UI version: 2021.1.330
• Browser: [all]