Release History

Telerik UI for ASP.NET AJAX 2025.4.1111 (2025 Q4)

November 12, 2025

What's New

NEW

• New SpeechToTextButton control.
• Introduce a Telerik UI for ASP.NET AJAX AI Coding Assistant that can be used through an MCP server.
• Introduced a Telerik Document Processing AI Coding Assistant for the PDF Processing library, which can be used through an MCP server.
• SpreadProcessing: Added support for querying and summarizing Workbook content using AI, enabling users to interact with and extract insights from Workbooks.
• PdfProcessing: Introduced extended digital signature support. You can now externally sign the document hash and also use a TimeStamp server.

Common

NEW

• Telerik Document Processing: CancelationTokenSourceFactory.CreateTokenSource(TimeSpan? timeSpan) now performs proper argument checking.

FIXED

• NullReferenceException in SkinRegistrar.GetAppSetting() when debugging with page.Site null.
• Sys.InvalidOperationException for duplicate enum registrations in CDN combined resources.

Editor

NEW

• Added a new StripJavaScriptUris content filter, enabled by default, to block dangerous JavaScript-based URI schemes in HTML attributes.

FIXED

• Script execution occurs when switching between Html to Design modes despite StripDomEventAttributes being enabled.

Breaking Changes

• The StripDomEventAttributes content filter is now enabled by default to improve protection against XSS attacks.

Grid

FIXED

• Active item style remains active while navigating through other items.
• When sort a grid with LightWeight render mode and export to Excel Biff format the sort expression is added to the header cells.
• Grid Client-Side "BETWEEN" Filter support for DateTime values.

HtmlChart

FIXED

• Box Plot/Candlestick Chart Error: Uncaught (in promise) ReferenceError: series is not defined

ImageGallery

FIXED

• CurrentScrollPosition is not synchronized when ThumbnailsAreaSettings EnableZoneScroll="true" and ShowScrollbar="true"

ListBox

FIXED

• Transfer button needs to be clicked twice to make it have effect in RadListBox with Transfer functionality

PdfProcessing

NEW

• Enabled Long-Term Validation (LTV).
• Introduced API for externally signing the document hash.
• Introduced support for writing a RadFixedPage containing widgets using the PdfPageStreamWriter.WriteContent() method.
• Implemented Group 3, 2-D encoding for TIFF images (CCITTFaxDecode).
• Import of documents with invalid Creation or Modification dates is now handled.
• Provided support for the PAdES-BES signature standard.
• Introduced support for encrypting documents with an AES-128 algorithm.
• Provided support for /TR (Transfer Function) property of SMask.
• Added Comfort and Extended levels for the ZUGFeRD invoice.
• Introduced API for signing a document using a TimeStamp server.

FIXED

• TextFormatProvider: Extra character spacing occurs after export.
• Registered fonts are lost when the code is executed on multiple threads.
• PDF/A-1a and PDF/A-2b fails VeraPdf verification when there is an element with opacity exported (StrokeAlphaConstant).
• An OutOfMemoryException: Insufficient memory to continue the execution of the program when importing a document larger than 2.1 GB.
• ListBoxField selection is lost after import-export when the normal appearance contains MarkedContent with an empty properties dictionary.
• An InvalidCastException is thrown when importing a document with structure attribute that has a version number.
• InvalidCastException is thrown when importing a document with a structure element with an indirect reference to an integer value.
• An ArgumentException is thrown when exporting a document with a Unicode character in the Document Info.
• Stream is not disposed from PdfStreamWriter or PdfFileSource classes when the Dispose method is not called explicitly.
• A NullReferenceException is thrown when RecalculateContent is called on the VariableContent widget with OpenTypeFont.
• Wrongly embedding Standard Fonts when PdfComplianceLevel.None.
• The appearance of a form field button is lost after import-export operation.
• A solid line appears over the dashed lines when generating PDF from SVG diagram.
• SkiaImageFormatProvider: SMask.Matte is not applied correctly.
• OutOfMemoryException is thrown when importing a large document with invalid cross-reference table.
• Object reference not set to an instance of an object is thrown when loading a PDF generated with PdfProcessing in PAC.
• A NullReferenceException is thrown when decoding the image with CCITTFaxDecode filter.
• Merging a document with RadioButtonFields throws ArgumentException: 'An item with the same key has already been added..
• Line width (LW) Graphic state property is lost on import.
• A KeyNotFoundException is thrown when importing a document with structure element that references a page that is not part of the page collection.
• Hidden fields appear after merging pdf documents.
• An encrypted documents with an AES-256 algorithm are opened as empty documents on Apple devices.
• Creating a document from an SVG image with a CapPathRound adds unexpected lines.
• An ArgumentNullException is thrown when importing a restricted, AES-encrypted document.
• An ArgumentException is thrown when importing a document with duplicated filed names.
• [WPF]A KeyNotFoundException when filing the fields in a specific document and saving it.
• An InvalidCastException is thrown and the form field is skipped when importing a document containing a single associated widget annotation (or terminal field) merged into the field dictionary.
• Underline is not properly exported when the paragraph has exact line spacing and the font size is small.
• The CIDToGIDMap value is exported as an indirect object when the value is a PdfString.
• When recalculated, the TextBox widget appearance is exported with the wrong text properties.
• Subscript text underline should be shifted down compared to normal text underline.
• An OutOfMemoryException is thrown when decoding large images with the CCITTFaxDecode filter.
• [WPF]More pages than document pages count are rendered when some page tree node is added multiple times in its Parent Kids collection.
• Highlight of the fields is lost on import.
• Fields are doubled according to ItextSharp after import/export. Update to itext version 9.2.0 or above to resolve this.
• Field border appearance is lost during import-export of the document.
• Adobe Reader corrupts the umlaut/diacritics characters when typing in TextBox field exported from PdfProcessing.

Breaking Changes

• Introduced timeout mechanism for TextFormatProvider, TextSearch, and TextPosition.

Slider

FIXED

• RadSlider last item label not centered when SmallChange equals LargeChange.

SpreadProcessing

NEW

• Introduced Export to JSON file format.
• Added support for querying and summarizing Workbook content using AI, enabling users to interact with and extract insights from Workbooks.

FIXED

• DataBar conditional formatting with middle axis cannot be created.
• ArgumentNullException: 'Value cannot be null. (Parameter 'key')' while importing a document with shared formulas and conditional formatting.
• ConditionalFormattingRange's Formattings collection is not correctly enumerated when there are rules with intermittent ranges.

SpreadStreamProcessing

FIXED

• Appending content to an existing workbook results in a corrupted document.

WordsProcessing

FIXED

• PdfFormatProvider: Tables should ignore the fixed preferred width with the value of 0.
• SdtBuilderFailureException when importing a document with picture SDT around a paragraph with bookmark and picture.
• Replace cannot match whole words with special characters at the start/end.
• Left indents with floating point values are imported as 0.
• InvalidOperationException when cloning a document containing fields spanning multiple paragraphs.
• Incorrect message when the found match is contained in several paragraphs.
• Hyperlinks with fragment identifiers are not resolved correctly.
• Exporting a Header/Footer with a content control with multiple paragraphs leads to an empty document.