Breaking Changes in 16.0.0

Updated on Aug 11, 2026

Date Inputs

• Removed the default localized aria-label text (for example, "Select date", "Select time", "Select date and time") from DatePicker, DateRangePicker, DateTimePicker, and TimePicker. Explicitly pass ariaLabel if your application relies on the previous default.

Editor

• The Editor component has been converted to a functional component. The EditorClassComponent export has been removed. When using a ref, type it as EditorHandle instead of the class instance type Editor.

Inputs

• The FlatColorPicker _gradientSettings property has been renamed to gradientSettings.
• The FlatColorPicker _paletteSettings property has been renamed to paletteSettings.
• Removed the default localized aria-label fallback text on Checkbox, ColorGradient, ColorPalette, OTPInput, RangeSlider, and Rating. Explicitly pass ariaLabel/aria-label if your application relies on the previous default.

Layout

• The initial opened/aria-expanded computation logic of TimelineCard has changed. Review your usage of TimelineCard to confirm the initial expanded state matches your expectations.

Scheduler

• The allDayEditor property type in SchedulerFormEditorProps changed from React.ComponentType<TargetlessChangeEvent<CheckboxProps & FieldProps, boolean>> to React.ComponentType<TargetlessChangeEvent<SwitchProps & FieldProps, boolean>>. The all-day toggle now uses a Switch instead of a Checkbox.
• The default header date format for AgendaView, DayView, MultiDayView, WeekView, WorkWeekView, TimelineView, and MultiDayTimelineView has changed from '{0:D}'/'{0:d}' (long/short date) to '{0:M}'/'{0:m}' (month/day). Explicitly set selectedDateFormat/selectedShortDateFormat to restore the previous default.
• The default localization text for multiple recurrence editor messages has changed: "Repeat" → "Repeats every", "Daily" → "Day", "Weekly" → "Week", "Monthly" → "Month", "Yearly" → "Year", "All Day Event" → "All Day", "End" → "Ends", "Repeat on" → "On", "Repeat every" → "Repeats every", "More events" → "more".
• The descriptionError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The descriptionLabel property has been removed from SchedulerFormEditorProps. The description field label is now rendered as an SVG icon.
• The endError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The endTimezoneCheckedEditor property has been removed from SchedulerFormEditorProps. The timezone toggle is now managed by a built-in button in the date/time section.
• The endTimezoneCheckedLabel property has been removed from SchedulerFormEditorProps. The timezone toggle is now managed by a built-in button in the date/time section.
• The endTimezoneEditor property type in SchedulerFormEditorProps changed from React.ComponentType<TargetlessChangeEvent<ComboBoxProps, string>> to React.ComponentType<TargetlessChangeEvent<DropDownListProps, string>>. The timezone editor now uses a DropDownList instead of a ComboBox.
• The endTimezoneError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The endTimezoneLabel property has been removed from SchedulerFormEditorProps. The timezone label is no longer rendered as a separate component.
• The onRemoveClick handler and the delete button (.k-event-actions > .k-event-delete) have been removed from the SchedulerItem component. Event deletion is now triggered from the edit form via the new onDelete prop on SchedulerFormProps.
• The resourceLabel property has been removed from SchedulerFormEditorProps. Resource labels are now rendered as SVG icons when SchedulerResource.svgIcon is set.
• The resourcesError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The SchedulerForm dialog no longer renders the k-scheduler-edit-dialog CSS class on the Dialog element. The dialog width is now set to 650 instead of minWidth: 400.
• The SchedulerForm dialog actions bar layout changed from 'start' to 'end', reversing the button order. The Save button no longer renders icon="save" / svgIcon={saveIcon}, and the Cancel button no longer renders icon="cancel" / svgIcon={cancelIcon}.
• The startError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The startTimezoneCheckedEditor property has been removed from SchedulerFormEditorProps. The timezone toggle is now managed by a built-in button in the date/time section.
• The startTimezoneCheckedLabel property has been removed from SchedulerFormEditorProps. The timezone toggle is now managed by a built-in button in the date/time section.
• The startTimezoneEditor property type in SchedulerFormEditorProps changed from React.ComponentType<TargetlessChangeEvent<ComboBoxProps & FieldProps, string>> to React.ComponentType<TargetlessChangeEvent<DropDownListProps & FieldProps, string>>. The timezone editor now uses a DropDownList instead of a ComboBox.
• The startTimezoneError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The startTimezoneLabel property has been removed from SchedulerFormEditorProps. The timezone label is no longer rendered as a separate component.
• The titleError property has been removed from SchedulerFormEditorProps. Inline field validation errors are no longer rendered by the form editor.
• The titleLabel property has been removed from SchedulerFormEditorProps. The title field label is now rendered as an SVG icon.

TreeList

• The TreeList component has been converted to a functional component. When using a ref, type it as TreeListHandle instead of the class instance type TreeList.
• TreeListDraggableRow has been converted to a forwardRef component. The ref now returns a TreeListDraggableRowHandle.
• TreeListEvent, TreeListKeyDownEvent, and TreeListSelectionChangeEvent generic type parameter default changed from TreeList to TreeListHandle.
• TreeListHeaderSelectionCell has been converted to a forwardRef component. The ref now returns a TreeListHeaderSelectionCellHandle.
• TreeListNoRecords now exposes a TreeListNoRecordsHandle ref type.

TreeView

• The TreeView component has been converted to a functional component. The TreeViewClassComponent export has been removed. When using a ref, type it as TreeViewHandle instead of the class instance type TreeView.
• TreeViewDragClue now exposes a TreeViewDragClueHandle ref type.

Upload

• The Upload component has been converted to a functional component. When using a ref, type it as UploadHandle instead of the class instance type Upload.
• Event generics on BaseUploadEvent, UploadOnAddEvent, UploadOnBeforeRemoveEvent, UploadOnBeforeUploadEvent, UploadOnCancelEvent, UploadOnProgressEvent, UploadOnRemoveEvent, and UploadOnStatusChangeEvent now reference UploadHandle instead of Upload.