The below exception is thrown when upgrading using latest Telerik UI for ASP.NET MVC extension.

Failed to execute command.

System.NotImplementedException: Not implemented (Exception from HRESULT: 0x80004001 (E_NOTIMPL)) 
at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo) 
at Microsoft.VisualStudio.CommonIDE.Solutions.Dte.DteGenericProject.GetFileName() 
at Telerik.VSX.Internal.VisualStudio.VisualStudioThreadHelper.<>c__DisplayClass1_0`1.<<RunInMainThread>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown --- 
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at Microsoft.VisualStudio.Threading.JoinableTask.CompleteOnCurrentThread() 
at Microsoft.VisualStudio.Threading.JoinableTask`1.CompleteOnCurrentThread() 
at Telerik.VSX.NuGet.NuGetPackageService.GetInstalledPackage(Project project, String packageName, Boolean isPackageNamePartial, Boolean ignoreCapabilityMatchCheck) 
at Telerik.VSX.Web.Helpers.ProjectWrap.GetMvcVersion() 
at Telerik.VSX.Web.Helpers.ProjectWrap.CheckIsProjectSupported() 
at Telerik.KendoUI.Mvc.VSX.Helpers.KendoUIMvcProjectWrap.CheckIsProjectSupported() 
at Telerik.KendoUI.Mvc.VSX.Helpers.ProjectSearcher.FilterTelerikSupportedLanguageProjects(List`1 projectsList) 
at Telerik.VSX.Internal.VisualStudio.VisualStudioThreadHelper.<>c__DisplayClass1_0`1.<<RunInMainThread>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown --- 
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at Microsoft.VisualStudio.Threading.JoinableTask.CompleteOnCurrentThread() 
at Microsoft.VisualStudio.Threading.JoinableTask`1.CompleteOnCurrentThread() 
at Telerik.KendoUI.Mvc.VSX.Helpers.ProjectSearcher.GetTelerikEnabledProjectsByMainAssemblyMvcVersion(TargetMvcVersion mvcVersion) 
at Telerik.KendoUI.Mvc.VSX.ProjectConfigurators.ProjectConfigurationTypeSelector.ShouldShowTargetMvcPage(TargetMvcVersion targetMvcVersion) 
at Telerik.KendoUI.Mvc.VSX.ProjectConfigurators.ProjectConfigurationTypeSelector.GetProjectUpgradePreWizardData(IScenarioDef template) 
at Telerik.KendoUI.Mvc.VSX.ProjectConfigurators.ProjectConfigurationTypeSelector.ProjectUpgrade(IPropertyDataDictionary additionalPreWizardData) 
at Telerik.KendoUI.Mvc.VSX.ProjectConfigurators.StreamlinedProjectConfiguration.StartUpgradeWizard() 
at Telerik.VSX.VSPackage.PackageBase.CommandCallback(Object sender, EventArgs e)

Bug report

The tables within the Editor are not exported correctly (do not fit in the exported pdf document) when resized before exporting.

Reproduction of the problem

1. Open the following demo.
   https://demos.telerik.com/kendo-ui/editor/pdf-export
2. Resize the column of the table.
3. Export to PDF.

Current behavior

The table does not fit in the exported document.

Expected/desired behavior

The table should fit in the document.

Environment

• Kendo UI version: 2022.2.510
• Browser: [all]

Hello,

We are using Telerik UI for ASP.NET MVC for an interactive map. We have added GeoJSON shapes to the map. We want to display tooltips on the shapes but have noticed that the mouse enter/leave and tooltip display seems somewhat broken. When the user has zoomed in or out, the events seem to sometimes not be triggered at all, until the user has panned.
The issues we found were also present in this example: https://demos.telerik.com/aspnet-mvc/map/geojson
To reproduce:
1. Zoom in or out, either with the mosue wheel or with the map controls.
2. Move the mouse over shapes and check if they get any tooltip or highlight. Some of the time it will be working normally, some of the time the changes do not happen at all. If the problem does not appear, repeat the previous step and test again.
3. Panning the map, either by click-dragging or with the map controls, fixes the issue until further zooming breaks it again.

Thanks,

Will

Bug report

When using MVVM generated DropDownList input decorated with required attribute the validation message is not displayed upon validation.

Reproduction of the problem

1. Run this dojo
2. Click on a slot to create an event
3. Select an item from the second DropDownList
4. Click Save

Current behavior

Upon clicking Save the validation fails, as the first input has a required attribute, but a validation message is not displayed.

Expected/desired behavior

On failed validation, a validation message should be displayed.

Environment

• Kendo UI version: 2020.1.406
• Browser: [all]

Bug report

When a table is created through the table wizard and cellspacing is set to 0, this value is ignored and the table is created with no cellspacing value. 0 is a valid value and it affects the appearance of the table, so it should not be equivalent to not setting cellspacing.

Reproduction of the problem

Reproducible in the demos.

1. Use the table wizard.
2. Set 0 as cellspacing value.
3. Create the table.
4. Inspect the table in the browser's dev tools.

Current behavior

The table has no cellspacing attribute.

Expected/desired behavior

The table has cellspacing set to 0.

Environment

• Kendo UI version: 2020.2.617
• jQuery version: x.y
• Browser: [all ]

View several folders in treeview of the filemanager:  folder1, folder2, folder3

select folder1

now Click and drag folder2 to folder3.

the folder1 moves to folder3.  

this is not desired.

can be reproduced in the demo

https://demos.telerik.com/aspnet-mvc/filemanager

We are using the Kendo UI for different components like Grid in our APS.Net MVC application. Currently we are experiencing an issue while exporting the Kendo grid to Excel from mobile (both android and ios). It shows the following warning message. The same works when exporting from a PC without any issue. Could you please help to resolve the issue.

Hello,

On MAC, command+c cut instead of copy when selected texts are in a table. To duplicate, please follow these steps.

1. Go here: https://demos.telerik.com/aspnet-mvc/editor

2. Insert a new table.

3. Add some text into the table.

4. Select texts in the table.

5. Press command+c on MAC.

Please advise.

Thank you.

Bug report

Reproduction of the problem

Dojo example.

1. Open the dev tools console.
2. Click on the button above the Editor.
3. The Editor value is logged in the console.
   Note this part in the content:

if (value == 1) { text += "<h2>Apple</h2>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.<br><br>>> APPLE Deutschland</a>";

4. Click on the "viewHtml" tool. In the popup do not make any changes to the content, just click on "Update".
5. Click on the button above the Editor.
   The mentioned part of the script tag now looks like this:

if (value == 1) { text += "<h2>Apple</h2>
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.<br><br>>> APPLE Deutschland</a>";

A js exception is thrown after this content is loaded in the div below the Editor, because of the line break after:

if (value == 1) { text += "<h2>Apple</h2>

Current behavior

The viewHtml modifies the content of script tags, which causes js logic to become invalid.

Expected/desired behavior

The viewHtml tool should not make changes to the content of script tags.

Environment

• Kendo UI version: 2020.3.1021
• jQuery version: x.y
• Browser: [all]

Hello,

I have problem with menu control. Sometimes its items are duplicated. To reproduce it do the following: 

- create a menu control;

- bind it to remote data source (to reproduce issue easier set some delay for server side method);

- hover on menu item (datasource request will start), fast leave menu item (don't wait until it open) and hover again (one more datasource request will start), leave it again (optional);

- wait some time until second request completed;

- open menu item.

As a result you will see duplicated menu items. This issue can be reproduced on your demo page https://demos.telerik.com/kendo-ui/menu/remote-data-binding.

Could you please suggest me some workaround for this?

BR,

Artsem

Bug report

If there is a Spreadsheet on a given page and we scroll the page down using the mouse wheel, once the scrolling stops over the Spreadsheet and we try to continue it, we cannot do it. If the Spreadsheet has defined rows that are not currently visible when the mouse wheel is moved, then Spreadsheet is being scrolled, not the current page.

If the Spreadsheet has a lower number of pre-defined rows that are all displayed on the component's initialization the scrolling is again not applying to the page. Instead, moving the mouse wheel doesn't do anything until the mouse cursor is moved outside the Spreadsheet.

Reproduction of the problem

1. Open this Dojo example and run it
2. Move the mouse cursor in the middle of the pane displaying the compiled code.
3. Use the mouse wheel to scroll down the page and stop the scrolling once the cursor is in the zone of the Spreadsheet
4. Scroll down again

Current behavior

Because the cursor is inside the Spreadsheet the page cannot be scrolled. If the rows configuration is commented, when the scrolling is started again, the Spreadsheet data will be scrolled.

Expected/desired behavior

If all the data in the Spreadsheet is displayed, moving the mouse wheel over the component should result in page scrolling. If there is data in the Spreadsheet, there should be some way to prevent the scrolling inside the component.

Environment

• Kendo UI version: 2020.1.114
• jQuery version: x.y
• Browser: [all]

Bug report

Class k-state-focused is not removed from DropDownlist on blur, if its filter input was clicked.

Reproduction of the problem

1. Use Events demo
2. Click on DropDownList to expand its dropdown.
3. Click on DropDownList's filter input.
4. Click on demo's title to blur the DropDownList

Current behavior

DropDownList appears focused as k-state-focus class is not removed from its span
<span unselectable="on" class="k-dropdown-wrap k-state-default k-state-focused">

Expected/desired behavior

DropDownList does not appear focused.

Environment

• Kendo UI version: 2019.2.619
• Browser: all

Bug report

The ClientGroupFooterTemplate and ClientFooterTemplate configuration lead to an invalid template error when strict CSP mode is enabled. There are no corresponding methods that accept a TemplateHandler.

Reproduction of the problem

@(Html.Kendo().Grid<TelerikMvcApp3.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).ClientGroupFooterTemplate("Total:").ClientFooterTemplate("Team Total");
    })
    .Groupable()
    .Pageable()
    .Sortable()
    .Scrollable()
    .Filterable()
    .HtmlAttributes(new { style = "height:550px;" })
    .DataSource(dataSource => dataSource
        .Ajax()
        .PageSize(20)
        .Read(read => read.Action("Orders_Read", "Home"))
    )
)


@(Html.Kendo().DeferredScriptFile())

Current behavior

JS exceptions on initializing the Grid and on attempting to group it by ShipCity.

Expected/desired behavior

CSP compatible templates.

Environment

• Kendo UI version: 2023.3.1114
• jQuery version: x.y
• Browser: [all]

Bug report

The kendoWindow does not appear on top of the kendoDialog, even when explicitly calling .toFront(). The z-index is not being updated correctly to bring the kendoWindow to the front.

Reproduction of the problem

1. Open the Dojo example - https://dojo.telerik.com/BrnfHeaO

Current behavior

The Dialog is displayed over the Window, although the Window toFront() method is used.

Expected/desired behavior

The kendoWindow (Dialog 2) should appear on top of the kendoDialog (Dialog 1) when opened, similar to the behavior in version 2024.1.130. When .toFront() is called on the kendoWindow, it should update the z-index appropriately and bring the window to the front, displaying it above all other dialogs/windows.

The issue is a regression starting with 2024.1.319

Workaround:

$("#dialog2").parents('.k-window')[0].style['z-index'] = 12000

Dojo - https://dojo.telerik.com/HmQpGqeB

Environment

• Kendo UI version: 2025.4.1111
• Browser: [all]

Currently, only the List and Number validation rules are supported when using Workbook.ToDocument();

• https://github.com/telerik/kendo/blob/master/dpl/Telerik.Web.Spreadsheet/Models/Workbook.ToDocument.cs#L221 

It happens when the type of validation is text or custom 

for example:

If I saved :

"validation": {
                "type": "reject",
                "comparerType": "custom",
                "dataType": "custom",
                "from": "AND(LEN(A2)<3)",
                "showButton": true,
                "allowNulls": true
              }

I get back:

"validation": {
                "type": "reject",
                "comparerType": "equalTo",
                "dataType": "number",
                "from": "=AND(LEN(A2)<3)",
                "to": "\"=\"",
                "allowNulls": true
              }

It happens also when the comparer type is text - it saves it as a number

Also when I use the create validator with your UI and choose a custom formula it can't be saved because the compare type is null. As a result, I must define manually the custom validator

### Bug report

When setting the NoDataTemplate() option to an empty string, the option is not serialized.

### Reproduction of the problem

1. Define an AutoComplete with NoDataTemplate("")

2. Search for a non-existing option and notice how the popup opens and displays the default "No data found" message. When initializing the AutoComplete with jQuery and the "noDataTemplate" is set to "", the popup does not open.

A REPL sample for reproduction: https://netcorerepl.telerik.com/cfkPEClS50FUVU5z00

### Expected/desired behavior

When the NoDataTemplate("") is set and there are no results, the popup must not open. The NoDataTemplate option must work equally when using either the AutoComplete HtmlHelper or Kendo UI for jQuery AutoComplete.

### Environment

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

Bug report

When the scrollable option is disabled, on resizing the browser window by making it more narrow, at certain point the columns stop resizing and the whole table goes out of the right border of the Grid. Reproducible with the SASS and LESS themes.

Reproduction of the problem

Dojo example: https://dojo.telerik.com/ItIrEzEY/3

1. Either resize the right pane or use Fullscreen and resize the browser window and make it narrower.

Current behavior

The table goes out of wrapping element (.k-grid).

Expected/desired behavior

The columns resize and the table remains within the borders of the Grid.

Environment

• Kendo UI version: 2023.1.117
• jQuery version: x.y
• Browser: [all]

### Bug report

When a specified Splitter pane has a defined minimum or maximum size, it does not resize as expected.

The last working version is 2024.3.1015.

### Reproduction of the problem

A Dojo sample for reporduction: https://dojo.telerik.com/XbuxxnfF

The left pane cannot be resized.

### Expected/desired behavior

The left pane must be resized up to 50%.

### Environment

* **Kendo UI version: 2025.3.825
* **jQuery version: 3.7.1
* **Browser: [all]

Bug report

Reproduction of the problem

Dojo: https://dojo.telerik.com/InusevuW/2

1. Click the resize handle on the right side of the the event and resize it so that it ends on June 10 at 9:00 AM.
2. Try to move the event so that it ends 1h later (e.g. at 10:00 AM) but don't drop it.

Current behavior

The event snaps to the last slot of June 10.
Resizing the event (1) then moving it to start 1h earlier (3PM) doesn't work either. Dropping the event at 3PM makes it appear incorrectly.

Expected/desired behavior

The slots the event spans over should be properly calculated and on moving the event it should snap to the hovered slots.

Environment

• Kendo UI version: 2021.2.511
• jQuery version: x.y
• Browser: [all ]

When binding a dropdown to a list (with .BindTo()) instead of a DataSource, none of the object's properties besides "Text" and "Value" are available in the Template, and will throw a ReferenceError that the property is not defined.

But this only occurs if the list of items it is bound to is of the type SelectListItem, or inherits from that type.

If the list is of items that do not inherit from SelectListItem, then all properties can be used in the Template with no error.

Screenshot of example project output:

Explanation:

Each dropdown on the page has a .Template() which simply displays the "Text" property and one other property (listed in each section's heading). Example: 

"#= Text # - #= Disabled #"

If the property is not working correctly, a unhandled ReferenceError will occur and the dropdown will fail to initialize. These failed rows are highlighted red.

This only occurs when the dropdowns use .BindTo() and a list of either SelectListItems or of a class that inherits from SelectListItem. The dropdowns bound to lists of CustomSelectListItem, which does not inherit, have no issue with the additional properties.

This bug has been occurring since at least 2021.3.1109, but I confirmed is still present in the latest version.