Release History

Telerik UI for ASP.NET AJAX 2026.2.519 (2026 Q2)

May 20, 2026

Common

NEW

• New SegmentedControl Component
• Telerik Document Processing Library (DPL) version (2026.2.519)

FIXED

• 500 "The cryptographic operation has failed" when loading combined resource URLs with EnableHandlerEncryption after URL rebuild
• 404 on combined resource URL when EnableHandlerEncryption is enabled — URL exceeds max length due to plaintext length check
• 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
• "The cryptographic operation has failed!" error when showing a hidden control and there is RadStyleSheetManager and EnableHandlerEncryption=true

AsyncUpload

FIXED

• RadAsyncUpload "Drop Files here" element remains visible when dragging a file quickly over and out of the DragZone

CheckBox

FIXED

• Screen readers announce "checked/ not checked" when CheckBox feature is disabled

ColorPicker

FIXED

• Web palette layout broken - first column misaligned from the rest (Lightweight renderer)
• Zooming breaks the colorpicker
• The colorpicker pallet is corrupted in Firefox with different Windows Screen zoom levels

DateRangePicker

FIXED

• RadDateRangePicker method set_rangeSelectionStartDate and set_rangeSelectionEndDate not working as expected

Editor

NEW

• ImageManager and RadFileExplorer now support .avif, .heif, .heic and .webp file extensions
• Ability to resize the table columns and rows with the mouse in the content area
• The StripJavaScriptUris content filter is improved

FIXED

• After pasting from MS Word, StripSpan does not work until a mode change to HTML and back to Design

Grid

FIXED

• Scrolling on a mobile (touch) device is impossible with the Lightweight RenderMode when an HTML element takes up the entire grid row
• The Grid's Horizontal scrollbar is not visible in iOS when the grid is empty

Input

NEW

• Password textbox with show/hide feature

ListBox

NEW

• Allow lazy loading of images with design-time templates

Navigation

NEW

• Add Separator feature to the RadNavigation control

NumericTextBox

FIXED

• The ShowSpinButtons and Right Alignment cause the number to disappear behind the spinners

Rating

FIXED

• Ratings not working with body margin 0

TabStrip

FIXED

• The tab text is not being read by the screen reader
• Accessibility issues - RadTabStrip and RadMultiPageView
• When keyboard navigation is enabled Tabs keep focus even after focusing other tabs
• Focus highlighting in TabStrip not working properly with Keyboard Navigation

ToggleButton

FIXED

• Icons in RadToggleButton disappear when using ConfirmSettings

PdfProcessing

NEW

• 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
• Import-export support for ShadingType 1
• Import-export support for ShadingType 4
• Import-export support for ShadingType 6
• Import-export support for ShadingType 7
• Exposed internal GrayColor object
• Introduced support for signing multiple Signature fields

FIXED

• А NullReferenceException is thrown when exporting a document with a Type 3 font with missing/invalid Unicode mapping
• PdfStreamWriter: Duplicated page content due to incorrect caching mechanism
• PdfStreamWriter: Slow performance during page splitting
• SkiaImageFormatProvider: NullReferenceException is thrown when exporting pages containing images with missing optional ColorSpace
• XMP metadata is unescaped during import-export
• Document password cannot be resolved when document produced by the library contains a SignatureField
• Hidden PDF layers are imported as visible
• An Invalid PDF document is exported when inserting a specific Jpeg image with an ICC profile
• A password is asked although Adobe opens the document without one
• A CryptographicException because MD5 not available on Blazor WASM
• Corrupted document when exporting Courier New subset
• NetStandard: Missing content due to empty glyph outlines in embedded TrueType font subsets

SpreadProcessing

NEW

• Cell rotation is now respected when exporting the workbook to PDF
• Introduce calculation chain functionality

FIXED

• Pasting a range in filtered rows overwrites their content
• Formatting string #.##0,00;-#.##0,00;;@ does not hide zero values
• Images don't move with cells when a row/column is inserted
• When setting value in a cell, certain strings are recognized as dates instead of as text
• PdfFormatProvider: NotSupportedException: 'No imaging component suitable to complete this operation was found.'
• PdfFormatProvider: NullReferenceException when exporting PatternFill with PatternType.DiagonalStripe
• Slow import for files with a lot of formulas

WordsProcessing

NEW

• Introduced support for the Markdown file format, allowing import/export from/to markdown format
• TxtFormatProvider: Introduced support for export of Lists

FIXED

• 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: Styles are not correctly preserved when a bold tag is applied to the same styled element