Bug report

When the TabStrip has an empty dataSource initially, and then a new item is added using the dataSource.add() an error appears in the console and no item is added.

Reproduction of the problem

1. Run the example and observe the console - https://dojo.telerik.com/nzQDTrjN

Current behavior

An error appears in the console, and no item is added.

Expected/desired behavior

An item should be correctly added in the TabStrip.

The issue is a regression starting with the KEndo version 2025.3.825

Workaround

Add an item in the dataSource initially and remove it when needed - Dojo - https://dojo.telerik.com/NgHHVOFy

Environment

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

Bug report

When a Notification is rendered on the same page as popups (Window, Dialog, etc), it is displayed behind the popup.

Reproduction of the problem

1. Open the Dojo examples - https://dojo.telerik.com/rvoPVbqK and https://dojo.telerik.com/mXdTrXpa

Current behavior

Notification is displayed behind the popups.

Expected/desired behavior

The Notification should be displayed on top of the popups

Workaround

 $('.k-notification').parents('.k-animation-container').css('z-index', 12500)

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

The issue is a regression starting with 2025.4.1111 version.

Environment

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

Bug report

In some cases, a CSP error - Applying inline style violates the following Content Security Policy directive 'style-src 'self' .... is thrown in the Editor

Reproduction of the problem

1. Open the Dojo - https://dojo.telerik.com/jOwrhome
2. Enter text and click on the tools. Note: the error does not appear consistently; You can follow the steps from the video below to replicate it (clicking on 'bold', 'align', 'unordered list')

Current behavior

CSP Error is thrown - Applying inline style violates the following Content Security Policy directive 'style-src 'self'

Expected/desired behavior

There should be no errors when using the Editor tools.

Environment

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

Bug report

When the sortable option is disabled, the title in the header is not wrapped in span element with 'k-column-title' class.

Reproduction of the problem

1. Open the Dojo and inspect the titles - https://dojo.telerik.com/hKCCsAOU

Current behavior

Rendering with sortable enabled:

The filtering icon and title have enough space:

Rendering with sortable disabled:

filtering icon overlaps the title in case of long text:

Expected/desired behavior

The rendering should be identical. The header title should be wrapped in a span element with 'k-column-title' class

Workaround for fixing the overlapping issue:

<style>
    .k-grid-header .k-filterable{
      padding-right: calc(1.42857143em + 14px);
    }
  </style>

Environment

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

Bug Report

When utilizing a scrollable, horizontal Kendo UI Menu, the height of the menu appears to stretch.

Reproducible

1. Go to this Progress Kendo UI Dojo.

Expected Behavior

The Menu's height should not stretch upon initialization as shown in this Progress Kendo UI Dojo.

Environment

• Kendo UI version: 2025.4.1111
• jQuery version: All Supported Versions
• Browser: all

The grid has a number of built in filters, what is not supported is searching for cells that have no value or some value (i.e. NULL or NOT NULL).
This would be a very useful addition.

Bug report

Using Edge/Chrome, upon pasting underline text in the Kendo UI Editor, the content is rendered underline, but the UI doesn't highlight the button. In turn, if the user toggles the underline style for parts of the text, it doesn't work. At this point, the button is now highlighted for the part, but switching back to no underline style doesn't have any effect regarding the rendering. Removing the style for the whole line does work as expected.

Reproduction of the problem

1. Open Editor demo and enter some text, containing an underline.

2. Copy the entered text and reload page
3. Paste content at the start of the document. The text is not recognized as underline text

4. Select part of the text and toggle underline. Part of the text is recognized as underlined text now.

Expected/desired behavior

The underlined text decoration should be recognized by the UI and display.

Additional Notes

As a comparison, here is the content after paste:

Edge/Chrome

<p><span style="text-decoration-line:underline;">some text with underline</span></p>

FireFox - which is working

<p><span style="text-decoration:underline;">some text with underline</span></p>

Environment

• Kendo UI version: 2023.1.314
• jQuery version: All supported versions
• Browser: Chrome 111.0.5563.111 | Edge 111.0.1661.54

Bug report

When a CheckBox is set to enabled: false, the input is missing the k-disabled class. Thus, the checkbox does not have disabled styles applied.

Reproduction of the problem

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

The desired rendering of the component - https://github.com/telerik/kendo-themes/blob/e1dbf1a74980bd82718f40085f6a8e21922f1897/tests/checkbox/checkbox-states.html#L44

Current behavior

The first checkbox is enabled and the second is disabled, but they appear the same.

Expected/desired behavior

The input should have the k-disabled class when the checkbox is disabled

Workaround

 <style>
        .k-checkbox:disabled{
          opacity: 0.6
        }
      </style>

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

Environment

• Kendo UI version: 2025.3.1002
• Browser: [all ]

Bug report

If you set a data validation for a number typed cell in the Spreadsheet, the message will be improperly formatted.

Regression introduced with 2024.4.1112

Reproduction of the problem

1. Open the Spreadsheet Overview demo - https://demos.telerik.com/kendo-ui/spreadsheet/index
2. Select an empty cell, and click Data Tab -> Data Validation
3. Select Number from the dropdown
4. Enter Min value
5. Check the Show hint box, and click apply
6. In the cell, type a value lower than the min

Current behavior

The validation message is improperly formatted - "Please enter a valid any value greater than 10,,10,,number,reject,greaterThan."

Expected/desired behavior

Message should be "Please enter a valid any value greater than 10."

Environment

• Kendo UI version: 2025.2.702
• Browser: [all]

Currently, Kendo UI for jQuery components rely on innerHTML and direct DOM manipulation throughout their internal implementation. This occurs in multiple components.

Thus, when "require-trusted-types-for 'script';" is included, errors such as - `This document requires 'TrustedHTML' assignment. The action has been blocked.` and `TypeError: Failed to execute 'write' on 'Document': This document requires 'TrustedHTML'` - appears on the page.

I would like to request Trusted Types Support for Kendo UI for jQuery components.

Hi Team,

I would like to request a preview above the Kendo UI ArcGauge to show the potential colors similar to the appearance of the RadialGauge.  

Thank you!

Bug report

When there is a filter applied in Excel file and the file is imported in the Spreadsheet only the first row is visible. The issue occur when the filtered column is a numeric column.

Reproduction of the problem

1. Open the Demos - https://demos.telerik.com/kendo-ui/spreadsheet/index
2. Import the file

Book1.xlsx

Current behavior

Only the filter row is visible. The filter result data rows are hidden:

Expected/desired behavior

All rows with filtered results should be visible. Example:

The issue is a regression starting with 2024.4.1112 release

Environment

• Kendo UI version: 2025.1.227
• Browser: [all ]

Bug report

When the formula PRODUCT is used and the content of the cell based on which the formula is calculated is deleted, the result is incorrect.

Reproduction of the problem

1. Open the Dojo - https://dojo.telerik.com/@NeliK/OKAQaGOv
2. Delete the content of the A1 cell

Current behavior

The result in B1 is 1, while it should be 0

Expected/desired behavior

When the content of the cell used for calculation is deleted, the product formula should result to 0 (as it is in Excel).

Environment

• Kendo UI version: 2024.3.806
• Browser: [all ]

Bug report

Spreadsheet fromFile() method does not return reject promise when an error occurs while loading file. An error is thrown on the browser console instead.

The issue has been tracked to the following implementation in the source:

• In the spreadsheet/workbook.js, the method fromFile() rejects the promise only when no file has been passed to the method code
• In the spreadsheet/excel-reader.js the method readWorkbook() should receive the deferred object as its last argument, but is renamed to progress and never used in the method;

Reproduction of the problem

• On the following Dojo select invalid file in the file input (.png, .pdf, .jpg or other);

Expected:

the 'No file to be loaded!' should be alerted;

Actual:

An error will be thrown on the console

Kendo version: 2023.3.1010

Bug report

Reproduction of the problem

Reproducible in the demos.

1. Use the HYPERLINK function in a cell:

=HYPERLINK("https://google.com")

Current behavior

The link does not work. It does if you specify a "friendly name":
=HYPERLINK("https://google.com", "google")

Expected/desired behavior

The link works with and without a "friendly name" specified, as in Excel.

Environment

• Kendo UI version: 2019.2.619
• jQuery version: x.y
• Browser: [all]

If you create a spreadsheet in excel and just have the below formula - it locks up when you activate the sheet. 

Or if you use the kendo spreadsheet and paste this into a cell, it also locks up.

=WORKDAY(TODAY(),-1)

Description

When the points in the ScatterLine chart are unevenly spaced, the resulting line may appear less smooth and have unexpected curve

Steps To Reproduce

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

Screenshots or video

Actual Behavior

The line may appear with an unexpected curve and is not smooth.

Expected Behavior

When the smooth option is enabled, the line should appear smooth with all the data.

Reported in TicketID: 1703639

Bug report

When a Grid is set to readonly mode, but it is also navigatable, and the user clicks on a cell and presses Tab, the next cell enters editable mode.

Reproduction of the problem

1. Open the Dojo - https://dojo.telerik.com/HXzAIqWR/3.
2. Click in a cell and press Tab.

Current behavior

The cell is editable.

Expected/desired behavior

When the Grid is in readonly mode, it should not be editable when navigating using the tab key.

Environment

• Kendo UI version: 2025.3.825
• Browser: [all ]

Hi Team,

I would like to request a built-in way to set a gradient area between line series.  

Thank you!

Bug report

In a Spreadsheet with date cell editor, the fr-CA culture does not work.

Reproduction of the problem

1. Open this Dojo example - https://dojo.telerik.com/ogEvuTEf/6
2. Open the editor for the date cell

Current behavior

The Calendar is empty

Expected/desired behavior

The Calendar should display the dates defined in the validation

Environment

• Kendo UI version: 2023.3.1114
• Browser: [all]