Telerik UI for ASP.NET AJAX 2026 Q3 (2026.3.812)2026年8月12日
機能
Common:
Added the Telerik.Web.UI.FileBrowserAllowedPaths web.config setting to restrict the folders accessible to RadEditor and RadFileExplorer's file browser dialogs.
Added the Telerik.PersistenceFramework.AllowedCustomTypes web.config setting to allow custom types used with the Persistence Framework (e.g. RadDock, RadGrid, RadPivotGrid state persistence).
Added the Telerik.Web.UI.AllowedCustomDialogTypes web.config setting to allow custom dialog types used with RadEditor dialogs during deserialization.
The Telerik.Upload.AllowedCustomMetaDataTypes, Telerik.Web.UI.AllowedCustomDialogTypes, and Telerik.PersistenceFramework.AllowedCustomTypes web.config settings now accept fully-qualified assembly names (FQAN), improving custom type resolution in Web Forms Site projects compiled on the fly.
Dependencies:
Telerik.Licensing version (1.9.1).
Telerik.Spreadsheet.Web version (1.2.0).
Telerik Document Processing Library (DPL) version (2026.3.810).
Chart (obsolete):
[Breaking Change] RadChart has been removed from the Telerik.Web.UI assembly. Applications that reference RadChart or its related classes must migrate to RadHtmlChart.
Spreadsheet:
[Breaking Change] The RadSpreadsheet dependency assembly has been renamed from Telerik.Web.Spreadsheet to Telerik.Spreadsheet.Web. Update project references accordingly. Telerik.Spreadsheet.Web is now publicly available as a separate package on NuGet and must be added explicitly.
修正
Security:
Ongoing security improvements.
Common:
Watermarks no longer appear on valid trial licenses.
AsyncUpload:
e.UploadResult in the FileUploadEvent throws InvalidOperationException: This type is not allowed.
Disabling session state and csrf causes null reference exception when using async upload.
MonthYearPicker:
RadMonthYearPicker is not rendered correctly when RenderMode is set to Lightweight in the web.config and TodayButtonCaption is defined.
Panelbar:
Accesskey on items not focusing them in PanelBar control.
PersistenceFramework:
Error: System.InvalidOperationException: This type is not allowed.
Spreadsheet:
A JavaScript error is thrown when typing a font size that is not presented in the dropdown.
Telerik UI for ASP.NET AJAX 2026 Q2 (2026.2.708)2026年7月8日
機能
Common:
Dependencies: Updated Telerik Document Processing Library (DPL) version to 2026.2.707.
Chart (obsolete):
Breaking Changes: RadChart is now marked as [Obsolete]. This is the last release that includes the RadChart component. Its source code will be removed from the assembly in the next release. RadChart has been deprecated since Q3 2014 and does not support modern browsers. Migrate to RadHtmlChart for a fully supported, standards-based charting solution.
DatePicker:
Invalid WAI-ARIA role, state or property for DatePicker.
DropDownTree:
Added WAI-ARIA support to RadDropDownTree keyboard navigation.
SegmentedComponent:
Provided SegmentedControl Designer for Visual Studio Design mode.
修正
Common:
Fixed Visual Studio Design time error rendering the control - Object reference not set to an instance of an object.
AutoCompleteBox:
JavaScript error (Uncaught TypeError: Cannot read property 'keyCode' of undefined) is thrown when selecting an autocomplete suggestion in Chromium browsers.
AsyncUpload:
Fixed issue where RadAsyncUpload can't be selected from RadTab using arrow key navigation.
ColorPicker:
Fixed issue where localizing RadColorPicker using Resource-files is not working.
Fixed issue where RadColorPicker remains clickable when disabled on client-side.
ComboBox:
Fixed RadComboBox infinite "Loading..." issue after upgrading to 2026.1.225.
DatePicker:
Fixed issue where Date/Time/DateTime Picker Items not aligned properly after Q2 update.
DropDownTree:
Fixed issue where RadDropDownTree With CheckBoxes="CheckChildNodes" and CheckChildNodes="false" has no effect.
Editor:
Track Changes - Fixed issue where table insertion loses its tracked change marker after creating a new paragraph.
Fixed issue where Nested Ordered/Unordered lists fail to maintain order in Chrome.
ListBox:
Fixed issue where RadListBox checked items are not available on the server if the control is enabled on the client.
Fixed issue where RadListBox resets scroll position to 0 upon item selection after mouse wheel scrolling.
NumericTextBox:
Fixed issue where NumericTextbox SpinButton layout changed with 2026.2.
Scheduler:
Fixed issue where the tooltips on the navigation buttons display "next day" and "previous day" when navigating month and week.
SearchBox:
Fixed issue where the "Show All Results" in SearchBox is not accessible with a keyboard.
Signature:
Fixed issue where changing the size of the Signature by changing the size of the viewport leads to the misplacement of the stroke.
Telerik UI for ASP.NET AJAX 2026 Q2 (2026.2.519)2026年5月20日
機能
Common:
Added new SegmentedControl component.
Updated Telerik Document Processing Library (DPL) version to 2026.2.519.
Editor:
ImageManager and RadFileExplorer now support .avif, .heif, .heic and .webp file extensions.
Added the ability to resize the table columns and rows with the mouse in the content area.
Improved the StripJavaScriptUris content filter.
Input:
Added password textbox with show/hide feature.
ListBox:
Allows lazy loading of images with design-time templates.
Navigation:
Added Separator feature to the RadNavigation control.
PdfProcessing:
Handled import of documents with missing/invalid rectangle (re) operands.
Handled invalid ASCII85Decode filter scenario - PDF streams where the end-of-data marker contains whitespace.
Added import-export support for ShadingType 1.
Added import-export support for ShadingType 4.
Added import-export support for ShadingType 6.
Added import-export support for ShadingType 7.
Exposed internal GrayColor object.
Introduced support for signing multiple Signature fields.
SpreadProcessing:
Cell rotation is now respected when exporting the workbook to PDF.
Introduced calculation chain functionality.
WordsProcessing:
Introduced support for the Markdown file format, allowing import/export from/to markdown format.
TxtFormatProvider: Introduced support for export of Lists.
修正
Common:
Fixed 500 "The cryptographic operation has failed" when loading combined resource URLs with EnableHandlerEncryption after URL rebuild.
Fixed 404 on combined resource URL when EnableHandlerEncryption is enabled - URL exceeds max length due to plaintext length check.
Fixed JS error when hovering a menu after partial postback when a RadButton is in an UpdatePanel and the Telerik.Web.UI.WebResource.axd URL is encrypted.
Fixed "The cryptographic operation has failed!" error when showing a hidden control and there is RadStyleSheetManager and EnableHandlerEncryption=true.
AsyncUpload:
Fixed issue where RadAsyncUpload "Drop Files here" element remains visible when dragging a file quickly over and out of the DragZone.
CheckBox:
Fixed issue where screen readers announce "checked/ not checked" when CheckBox feature is disabled.
ColorPicker:
Fixed broken web palette layout - first column misaligned from the rest (Lightweight renderer).
Fixed issue where zooming breaks the colorpicker.
Fixed issue where the colorpicker pallet is corrupted in Firefox with different Windows Screen zoom levels.
DateRangePicker:
Fixed issue where RadDateRangePicker method set_rangeSelectionStartDate and set_rangeSelectionEndDate are not working as expected.
Editor:
Fixed issue after pasting from MS Word, where StripSpan does not work until a mode change to HTML and back to Design.
Grid:
Fixed issue where scrolling on a mobile (touch) device is impossible with the Lightweight RenderMode when an HTML element takes up the entire grid row.
Fixed issue where the Grid's Horizontal scrollbar is not visible in iOS when the grid is empty.
NumericTextBox:
Fixed issue where the ShowSpinButtons and Right Alignment cause the number to disappear behind the spinners.
Rating:
Fixed issue where ratings are not working with body margin 0.
TabStrip:
Fixed issue where the tab text is not being read by the screen reader.
Fixed accessibility issues for RadTabStrip and RadMultiPageView.
Fixed issue when keyboard navigation is enabled Tabs keep focus even after focusing other tabs.
Fixed issue where focus highlighting in TabStrip is not working properly with Keyboard Navigation.
ToggleButton:
Fixed issue where icons in RadToggleButton disappear when using ConfirmSettings.
PdfProcessing:
Fixed issue where a NullReferenceException is thrown when exporting a document with a Type 3 font with missing/invalid Unicode mapping.
PdfStreamWriter: Fixed issue regarding duplicated page content due to incorrect caching mechanism.
PdfStreamWriter: Fixed slow performance during page splitting.
SkiaImageFormatProvider: Fixed issue where NullReferenceException is thrown when exporting pages containing images with missing optional ColorSpace.
Fixed issue where XMP metadata is unescaped during import-export.
Fixed issue where document password cannot be resolved when document produced by the library contains a SignatureField.
Fixed issue where hidden PDF layers are imported as visible.
Fixed issue where an invalid PDF document is exported when inserting a specific Jpeg image with an ICC profile.
Fixed issue where a password is asked although Adobe opens the document without one.
Fixed CryptographicException because MD5 not available on Blazor WASM.
Fixed corrupted document when exporting Courier New subset.
NetStandard: Fixed missing content due to empty glyph outlines in embedded TrueType font subsets.
SpreadProcessing:
Fixed issue where pasting a range in filtered rows overwrites their content.
Fixed issue where formatting string #.##0,00;-#.##0,00;;@ does not hide zero values.
Fixed issue where images don't move with cells when a row/column is inserted.
Fixed issue when setting value in a cell, where certain strings are recognized as dates instead of as text.
PdfFormatProvider: Fixed NotSupportedException: 'No imaging component suitable to complete this operation was found.'.
PdfFormatProvider: Fixed NullReferenceException when exporting PatternFill with PatternType.DiagonalStripe.
Fixed slow import for files with a lot of formulas.
WordsProcessing:
Fixed issue where font of a style is changed on RTF import when the font is not explicitly defined in the style, and default character properties have font defined or is missing altogether.
HtmlFormatProvider: Fixed issue where styles are not correctly preserved when a bold tag is applied to the same styled element.
Telerik UI for ASP.NET AJAX 2026 Q1 (2026.1.421)2026年4月22日
機能
Common:
Updated Telerik Licensing minimal required version to 1.8.2.
Updated Telerik Document Processing Library (DPL) version to 2026.1.402.
AsyncUpload (Breaking Changes):
CSRF validation is now enabled by default for all upload requests. Applications that do not use ASP.NET Session State must add to appSettings. Applications using WebResourceSession handler are not affected.
The legacy and already obsolete IFrame, Silverlight and Flash upload modules have been removed. RadAsyncUpload now exclusively uses the File API module.
The DisablePlugins property has been removed. Remove any references to it from your markup or code-behind.
The get_loadedModuleName() client-side method has been removed. Remove any calls to it from your client-side code.
The FileFilters property is no longer functional as it relied on the removed Flash and Silverlight modules. Use the HTML5 accept attribute on the file input instead.
The Telerik.Web.UI.RadAsyncUpload.Modules.Flash and Telerik.Web.UI.RadAsyncUpload.Modules.Silverlight client-side objects no longer exist. Remove any JavaScript workarounds referencing them.
ClientDataSource:
Added OData v4 transport option.
Editor:
MediaManager now outputs HTML5 video and audio elements for browser-supported formats (mp4, webm, ogv, mp3, wav, ogg, oga) instead of the obsolete object/embed tags. Legacy formats (e.g. avi, wmv) still use embed. The WMP Properties tab has been replaced with HTML5 attributes (controls, autoplay, loop, muted, preload) for supported formats.
Improved keyboard navigation and screen reader support in RadEditor toolbar dropdowns (FontName, FontSize, RealFontSize, ForeColor, BackColor, InsertSymbol, InsertTable etc.).
NumericTextBox:
Added EnableMobilePattern property for triggering the numeric keyboard on mobile devices.
PdfProcessing:
Optimized the export of Functions.
Improved font handling during document import.
Introduced API for Cloning RadFixedPages and for splitting RadFixedDocument into pages.
Implement AutoTag Tables from document Primitives.
Introduced support for PDF Portfolios.
Implemented Exponential Interpolation Function.
SpreadProcessing:
XlsFormatProvider: Added support for hidden rows.
Added support for Superscript/Subscript formatting option.
Introduced support for notes in XLS format.
Added support for Strikethrough formatting option.
Introduced support for images when importing and exporting XLS documents.
Design rendering failure with Uncaught TypeError: Cannot read properties of null (reading 'commonAncestorContainer') when using ToolbarMode="RibbonBarShowOnFocus".
Fixed issue where keyboard selection is not working in toolbar dropdowns (FontName, FontSize, RealFontSize).
Missing ARIA attributes on the HTML mode textarea when EnableAriaSupport is enabled.
Cell Properties - Preview only shows top-left cell styling when applying changes to multiple top-row cells.
Grid:
Fixed HeaderContext filter menu throwing '_linkElement' undefined error after expand animation ends.
PdfProcessing:
The import performance is reduced when having XObject instances with many Shading elements.
PdfStreamWriter: Merging PDF documents causes blank pages.
Fixed issue where an InvalidCastException is thrown when importing a document.
Fixed issue where a NullReferenceException is thrown when importing a document with EmbeddedFile without Subtype.
SpeechToTextButton:
Fixed SpeechToTextButton Designer throwing an error at design time.
SpreadProcessing:
SpreadProcessing: XLSX image lock aspect ratio imports incorrectly when importing a document with PictureLockingElement which noChangeAspect attribute is boolean.
XlsFormatProvider: InvalidOperationException is thrown when importing a document with an unsupported BIFF record.
Importing file with comments part with other name than comments.xml throws an exception.
Window:
RadWindow predefined dialogs do not fully expose required accessibility attributes.
WordsProcessing:
PdfFormatProvider: Justified text alignment is not respected for specific text content.
Telerik UI for ASP.NET AJAX 2026 Q1 (2026.1.225)2026年2月25日
機能
SmartPasteButton:
Added Visual Studio Designer support for RadSmartPasteButton.
Added RenderMode support for RadSmartPasteButton.
修正
Security:
Addressed an insufficient entropy vulnerability.
External jQuery scripts are now loaded through a Telerik Handler that ensures correct load order and restricts sources to trusted CDN hosts.
Common:
Fixed ReferenceError: kendo is not defined in version 2026 Q1.
Editor:
Fixed issue where duplicate toolbars are rendered when ToolProviderID is used with programmatically added Tools.
Gantt:
Fixed issue where RadGantt throws: Uncaught ReferenceError: kendo is not defined.
HtmlChart:
Fixed issue where the HtmlChart throws: Uncaught ReferenceError: kendo is not defined.
Fixed Uncaught TypeError: Cannot read properties of undefined (reading 'toLowerCase').
SearchBox:
Fixed the EnableAriaSupport ClientPropertyName mismatch.
Spreadsheet:
Fixed issue where Spreadsheet throws: Uncaught ReferenceError: kendo is not defined.
Telerik UI for ASP.NET AJAX 2026 Q1 (2026.1.211)メジャーバージョン2026年2月11日
機能
Common
Added a new SmartPasteButton component.
Telerik Licensing minimal required version has been updated to 1.6.40.
Integrated the latest Kendo UI scripts 2026.1.208 as a foundation for delivering new capabilities such as Smart Components.
Breaking Changes - Encapsulated the old embedded Kendo scripts to allow coexistence with externally referenced Kendo scripts on the same page. To disable the Embedded jQuery, you must set the EnableEmbeddedjQuery="false" and ExternaljQueryUrl="link_to_your_jQuery".
DropDownTree
Introduced RTL support for RadDropDownTree.
Editor
Added ARIA attributes to HTML mode textarea when EnableAriaSupport is set to enable.
PdfProcessing
PdfStreamSigner: Introduced TimeStamp server support.
Improved PDF digital signing to comply with European Commission validation requirements.
SearchBox
Added WAI-ARIA support in RadSearchBox.
修正
DocumentProcessing
Incorrect annotation border array is rendered instead of being skipped.
File format detection misidentifies .dot files as .doc/.txt.
Editor
Dialog titles for "Remove All Changes" and "Accept/Reject All Changes" are not fully localized.
The size of the Window in the Hyperlink Manager dialog in Bootstrap Classic skin is not tall enough.
The sizes of the Document Manager and Generate ID buttons in the Hyperlink Manager dialog in Bootstrap Lightweight is not correct.
The File Browser dialogs display scrollbars when AutoSize is enabled with LightweightRenderMode.
InsertLink dialog: Label "for" attribute case mismatch causes accessibility tools to report unlabeled control.
ListBox
RadListBox with CheckBoxes scrolls to previously active item when checking items after scrolling.
OTPInput
OTP input box is broken.
PdfProcessing
Wrong transformation of glyph data.
SkiaImageFormatProvider: Blacked out images due to incorrectly resolved clipping.
SkiaImageFormatProvider: Black images are exported for certain pages.
An InvalidOperationException is thrown when parser incorrectly interprets delimiter characters within literal strings as structural tokens instead of string data.
Failing to load an image prevents the PDF document from loading properly.
CryptographicException is thrown when importing AES encrypted document with DocumentInfo.
SpreadProcessing
LocalizableException is thrown after removing columns from a workbook with set Print Titles.
TabStrip
ScrollBars not working after tab switch.
Window
AutoSize shows a scroll in Chrome.
Scroll jumps to top when clicking dropdown controls with ShowContentDuringLoad="false" in Lightweight mode.
WordsProcessing
NullReferenceException is thrown when exporting a document with custom geometry.
Telerik UI for ASP.NET AJAX 2025 Q4 (2025.4.1321)2026年1月21日
機能
Common:
Updated Telerik Licensing minimal required version to 1.6.36.
Multiple accessibility and keyboard navigation improvements in multiple controls (RadListBox, OrgChart, TabStrip, Date/Time Pickers, MediaPlayer).
Telerik Document Processing: Introduced API for automatic file format detection.
ListBox:
Added WAI-ARIA support for RadListBox.
MediaPlayer:
Added Loop boolean property for video repeat support.
OrgChart:
Added keyboard navigation and Section 508 accessibility support.
PdfProcessing:
Handled documents with invalid byte offsets due to content added at the beginning of the file.
Introduced support for vertical alignment of table cells.
Handled the import of incrementally updated documents with invalid cross-reference offsets.
Handled the import of documents containing integers bigger than int.MaxValue.
Introduced API used to sign documents using only the end certificate of a certificate chain.
Introduced a mechanism for changing the Standard font when exporting a PDF/A Compliance document.
Handled import of documents with a negative cross-reference stream offset.
Handled the import of documents with invalid offset and no space before dictionary keys.
Added support for documents with an invalid stream cross-reference table.
Introduced support for Border annotation property.
Provided support for specifying the MIME type of embedded files.
修正
Calendar:
Fixed issue where Date and Time Pickers show picker button on the wrong side in RTL with Bootstrap skin and Lightweight rendering.
Docking:
Fixed issue where Dock width increases each time it is dropped with animation enabled.
Editor:
Fixed issue where StripCssExpressions filter causes performance degradation.
Fixed issue where incorrect event args are passed to RadEditor OnClientCommandExecuting when RadTreeList is present on the page.
Fixed issue where PdfExportFilter filter strips the width attribute from table elements when switching to HTML mode.
Grid:
Fixed issue where tableView.clearSort() does not remove sorted column visual state in client-side bound Grid.
ListBox:
Fixed issue where RadListBox lacks visible keyboard focus and proper ARIA support.
Fixed issue where the required WAI-ARIA attributes are missing in RadListBox button area toolbar and buttons.
PdfProcessing:
Fixed issue where a document with invalid cross-reference stream is not loaded correctly.
Fixed an InvalidOperationException: 'The signature was not properly initialized for external signing. The signing delegate is missing.'.
Fixed issue where re-saving a document with Acrobat throws an error due to invalid Info dictionary in document trailer.
Fixed issue where a MissingMethodException is thrown when converting PDF stream to PdfArray.
Fixed issue regarding mangled Right-To-Left (RTL) content when multiple lines of text are drawn.
Fixed issue where the font subset is not recalculated when you import-export a document and FontEmbeddingType.Subset set.
Fixed issue where some characters are not properly resolved from the Encoding differences table.
PdfStreamWriter: Fixed issue where InvalidOperationException is thrown when creating multi-page document with umlaut on the last page.
Fixed InvalidOperationException: 'isContentReleased' when exporting.
Fixed issue where the embedded font program is not consistent with the Widths entry of the font dictionary.
Fixed issue where CheckBoxWidget appearance is not correctly displayed when importing document with PdfProcessing.
Splitter:
Fixed issue where dragging the SplitBar moves the whole page slightly on mobile devices.
Fixed issue where SplitBar does not move smoothly on mobile devices, only shifts a few pixels when dragged.
SpreadStreamProcessing:
Fixed issue where files exported with SpreadStreamProcessing cannot be read by OleDB consumers.
TabStrip:
Fixed issue where focused tab CSS class is not removed when clicking tabs with mouse after keyboard navigation.
WordsProcessing:
Fixed issue where the w:multiLine property of a text content control is lost during import.
PdfFormatProvider: Fixed issue where tab stop distances are not calculated correctly when a hanging indent is applied.
HtmlFormatProvider: Fixed issue where a NullReferenceException is thrown when exporting a document that contains styles with no ParagraphMarkerProperties.
Fixed issue where content is moved to previous page after applying styling to the footer and exporting to PDF format.