Hi there, 

I am using Kendo UI version 2026.2.520. I have a gantt chart and the view options (day, week, month etc.) disappears when I change the width of the chart. However, when I change the version to 2025.2.520, the same width shows the view types. Is there some way to solve this issue so it was working as it previously did?

Here is the dojo I used

https://dojo.telerik.com/KQpoYmVQ 

Bug report

Long Gantt event is not visible since 2022.1.119

Reproduction of the problem

1. Open the Gantt Demo in Firefox.
2. Switch the view to Month.
3. Pick an event row in the chart (e.g. 'Market Research'), and set the End date to 2024-12-31.
4. The event is no longer visible in the right-hand-side of the gantt.

Expected/desired behavior

Gantt event shall be visible

Environment
Kendo UI version: 2022.1.119 or newer
Browser: [all]

When the RowHeight of the Gantt is enabled and the planned tasks are shown, the height of the row in the timeline is miscalculated and that creates displacement. 

• https://dojo.telerik.com/EgiGiXUF/5 

Additionally, the task dots used for the dependencies are misplaced in the same scenario as demonstrated in the dojo above. 

When selecting the Month View of the Gantt, unexpected blank space appears and the cell headers are not properly aligned.

To reproduce the problem, open this demo:
https://demos.telerik.com/kendo-ui/gantt/basic-usage

And Click Edit in Kendo UI Dojo:
https://dojo.telerik.com/OparoYUJ

Zoom out the browser so the Gantt has some larger Width and you will notice the blank space + misaligned headers:

The same issue can be observed in the Getting article: https://docs.telerik.com/kendo-ui/controls/gantt/get-started

Bug report

When tasks on the same level are dragged and dropped in order to change their relationship as parent - child, the entire Gantt collapses

Reproduction of the problem

1. Open the Dojo - https://dojo.telerik.com/@NeliK/EZOXuguC
2. Expand 'Task 1'
3. Drag Task 4 over Task 5 and drop it so it could become its child

Current behavior

The entire Gantt is collapsed.

Expected/desired behavior

The current expanded/collapsed state should not be changed.

The issue is a regression starting with version 2020.3.1021

Environment

• Kendo UI version: 2024.2.514
• Browser: [all ]

Bug report

When the culture is changed the NumericTextBox with decimals does not accept valid values when it is rendered inside an editable popup. The issue can be observed when the NumericTextBox is rendered for editing in other components such as Gantt and Grid.

Reproduction of the problem

1. Open the Dojo - https://dojo.telerik.com/@gdenchev/UKAVAnaZ
2. Try to edit a cell and decrease the number either by entering digits or by using the arrows.

Current behavior

A validation error that the value is not valid appears.
The same behavior occurs in the Gantt component if you try to edit a task, then select Resources and try to edit the Units value - https://dojo.telerik.com/@NeliK/uZepIbId

Expected/desired behavior

The value of the NumericTextBox should accept changes when the culture is set.

Environment

• Kendo UI version: 2024.1.319
• jQuery version: x.y
• Browser: [all ]

Bug report

When there is a selected item and filtering is performed in the Gantt, sometimes a task in the new filter result is displayed as selected.

Reproduction of the problem

1. Open the demo - https://demos.telerik.com/kendo-ui/gantt/columns
2. Filter the tasks by ID 18
3. Select the task with ID = 18
4. Filter the tasks that have ID equal to 11

Current behavior

Sometimes the task with ID 11 is marked as selected. The issue does not appear consistently, so you may need to perform the test multiple times.
screencast - https://somup.com/c0XZ6DgaRA

Expected/desired behavior

The tasks that have not been selected, should not be displayed as selected after filtering.

The issue is a regression starting with the 2022 R1 release

Environment

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

Bug report

Error is thrown in the console when an event is dragged.

Reproduction of the problem
Dojo: https://dojo.telerik.com/ORuSEYoW

Expected/desired behavior
Error shall not appear

Environment
Kendo UI version: [all]
jQuery version: [all]
Browser: all

Bug report

The dependencies in the Gantt can not be removed.

Reproduction of the problem

1. Open the demos - https://demos.telerik.com/kendo-ui/gantt/index
2. Select a dependency line and press the 'Delete' key.

Current behavior

Nothing happens, there is no confirmation popup, and the dependency is not removed.

Expected/desired behavior

A confirmation dialog for confirming the deletion appears and the dependency should be removed.

The issue is a regression starting with the 2023 R2 SP1 ( 2023.2.718) version

Environment

• Kendo UI version: 2023.2.718
• Browser: [all ]

Bug report

If you expand/collapse the top parent node, it is marked as dirty.

Regression introduced with R1 2023

Reproduction of the problem

1. Open the Gantt Overview demo - https://demos.telerik.com/kendo-ui/gantt/index
2. Collapse the top node

Current behavior

The top node is marked as dirty when collapsed

Expected/desired behavior

The top note shouldn't be marked as dirty upon collapsing

Environment

• Kendo UI version: 2023.1.314
• Browser: [all]

As all grids, the kendo Gantt chart's rows change their color when hovering. However, the background overlaps the border between columns and makes them disappear for the hovered row.

You can reproduce the described behavior by hovering one of the rows in this DOJO.

Bug report

The change event incorrectly triggers at initialization of the Gantt - Regression with 2022.1.301
Also, the event does not trigger when selecting a task from the timeline - Regression with 2022.3.913

Reproduction of the problem

1. Open this example - https://dojo.telerik.com/@martin.tabakov@progress.com/OVigiKEX/3
2. Check the Kendo Console - the change event triggers right after initialization
3. Select a task from the Gantt timeline - the change event doesn't trigger

Current behavior

Change event triggers after initialization and does not trigger after selection in timeline

Expected/desired behavior

Change event shouldn't trigger after initialization and should after selection in timeline

Environment

• Kendo UI version: 2022.3.1109
• Browser: [all]

Bug report

When you collapse a selected task in the Gantt, the selection is lost

Reproduction of the problem

1. Open the Gantt Overview demo - https://demos.telerik.com/kendo-ui/gantt/index
2. Select the Software validation task
3. Collapse the selected task

Current behavior

The selection is lost

Expected/desired behavior

The selection should be preserved

Environment

• Kendo UI version: 2022.2.802
• Browser: [all]

Bug report

When there are Grid and Gantt on the same page and a column in the Gantt has reordered an error in the console is thrown:
kendo.all.js:133531 Uncaught TypeError: Cannot read properties of undefined (reading 'lockable')

Reproduction of the problem

1. Open the Dojo. There is no relation in the configuration between the Grid and the Gantt widgets.
2. Reorder the columns in Gantt

Current behavior

The following error is thrown:
kendo.all.js:133531 Uncaught TypeError: Cannot read properties of undefined (reading 'lockable')

Expected/desired behavior

There should be no error in the console when reordering columns in Gantt, even if there is a Grid on the page.

The issue is a regression starting with: 2021.3.1207

Environment

• Kendo UI version: 2022.2.802
• Browser: [all]

Bug report

In a Gantt that has a DropDownList as editor in the TreeList, if you click on the DropDownList's wrapper to open the widget, it will close the cell instead.

Regression introduced with 2022 R1

Reproduction of the problem

1. Open this example - https://dojo.telerik.com/OlOCIkOZ/3
2. Double click to edit the Status field
3. Click on the DropDownList wrapper.

Current behavior

The cell closes.

Expected/desired behavior

The cell should remain open and the DropDownList should open

Environment

• Kendo UI version: 2022.2.621
• Browser: [all]

Bug report

When the duration of a task is edited in the Task Duration column in Gantt in the save event handler e.task.taskDuration returns the new duration value. With versions, before 2020 R3, the old task duration value has been returned.

Reproduction of the problem

1. Open the Dojo
2. Edit the value in the 'Task Duration' column and observe the result in the browser`s console.

Current behavior

With the current version, the new task duration is returned.

Expected/desired behavior

The returned e.task.taskDuration should return the previous task duration in order to be consistent with the behavior before 2020 R3

Regression since 2020.3.915

Environment

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

Bug report

With e.preventDefault in the save event of the Gantt, the TreeList becomes unresponsive when blurring a task field.

Reproduction of the problem

1. Open this example - https://dojo.telerik.com/aWaHadaL/17
2. Add a child task under Task 1.
3. Double click on a field of the Child task in the TreeList.
4. Blur the element.

Current behavior

The parent task collapses and becomes unresponsive

Expected/desired behavior

The parent task should not collapse and become unresponsive

Environment

• Kendo UI version: 2022.1.412
• Browser: [all]

Bug report

When the end date of a task is edited in the End Time column in Gantt in the save event handler e.task.end returns the new end date value. With versions, before 2020 R3, the old end task value has been returned.
The behavior is inconsistent with editing a task through dragging or by double-clicking on a task as in such case the previous value of the end task will be returned

Reproduction of the problem

1. Open the Dojo
2. Edit the date in the 'End Time' column and observe the result in the browser`s console.

Current behavior

With the current version, the new end date is returned.

Expected/desired behavior

The returned e.task.end should be consistent with the other ways of changing the date e.g. dragging or double-clicking on the task.

Regression since 2020.3.915

Environment

• Kendo UI version: 2022.1.412
• Browser: [all]

Bug report

If a date is configured in Gantt by using the date method or views.date configuration and then a task is edited, the Gantt displays the initial date after editing a task.

Reproduction of the problem

1. Open the Dojo
2. Scroll horizontally and edit a task (for example 'Architecture')

Current behavior

After the task is edited the horizontal scroll position is set to its initial position, not to a position according to the edited task. Thus, the user needs to scroll again in order to find the edited task.
The behavior is not the same when the date method/configuration is not used. Also, the behavior is not the same if we first switch between the 'Day', 'Week', 'Month' views before editing a task.

Expected/desired behavior

Even if the initial date of the Gantt is configured, when the user edits a task, the date should not be persisted. The horizontal scroll should be in the same position as before editing a task.

Environment

• Kendo UI version: 2021.3.1109
• Browser: [all ]

Bug report

When tasks are reordered in Gantt duplicated requests are sent for updating.

Reproduction of the problem

1. Open the Gantt Overview Demo
2. Reorder two tasks and inspect the requests in the Network tab

Current behavior

For example, in case two tasks on the same level are changing their places, four requests are sent, two by two the requests are the same.
In case a task is moved on a different level multiple requests are sent, as all are duplicated.

Expected/desired behavior

There should be no duplicated requests when reordering tasks in Gantt

This is a regression introduced with R3 2020 (2020.3.915)

Environment

• Kendo UI version: 2021.3.914
• Browser: [all ]