Release Notes

26.8.0

August 31, 2026

Platform Updates

New Release: Doconut is now available for .NET Standard 2.1, bringing the current API, the plugin model and the distributed deployment path to any application targeting .NET Core 3.0 or later.
New Release: The .NET Standard 2.1 package ships the core viewer with annotations and advanced search built in, plus the Converter and DICOM plugins.
Enhancement: Two ready-to-run sample applications ship with the release - a single-node MVC viewer and a multi-node sample serving the same documents from one shared folder - alongside a step-by-step upgrade guide.
Enhancement: Improved format detection for XHTML files so password-protection checks classify them correctly.

Breaking Change: The Doconut.NETStandard package moves from .NET Standard 2.0 to .NET Standard 2.1 under the same package id. Version 26.7.0 and below is the previous API; 26.8.0 and above is the new one. There is no compatibility shim, so raising the version number is the upgrade - review the upgrade guide before you bump it.
Breaking Change: The web farm middleware is no longer part of the API. Multi-node deployments now publish the document artifacts into the shared folder and serve them from any node through the distributed file share handler. The shared folder itself is unchanged, and the included distributed sample shows the new bootstrap end to end.

Bug Fix: Fixed an error that could interrupt rendering when a document's fields are refreshed before the page is displayed.
Bug Fix: Improved character placement so rendered Word pages match the source document more closely.
Bug Fix: Corrected the indent of bulleted lists in rendered Word pages.

Bug Fix: Fixed images being dropped when converting Word documents to PDF.
Bug Fix: Removed an extra blank page that could be appended when converting Word documents to PDF.
Enhancement: Reduced the size of SVG output for documents containing equations, which previously embedded the full font glyph set.

Bug Fix: Fixed a failure that could occur when rendering worksheets containing certain charts or images.

Bug Fix: Pie charts now keep their original size when converting spreadsheets to PDF.
Bug Fix: Corrected line spacing inside worksheet text boxes when converting spreadsheets to PDF.
Bug Fix: Shapes and drawing objects now keep their position when converting spreadsheets to PDF, and hidden shapes stay hidden.
Bug Fix: Embedded images now keep their original colors when converting spreadsheets to PDF.

Bug Fix: Connector lines between shapes now appear in rendered Visio pages instead of being missing until the diagram is edited.
Bug Fix: Header text inside container shapes now renders in the correct position.
Bug Fix: Text inside grouped shapes is now measured correctly, so labels are no longer clipped or overflowing.

Bug Fix: Rendered Photoshop files now keep the brightness of the source image instead of appearing noticeably darker.
Bug Fix: Photoshop files using a complex Liquify smart filter now open instead of failing to load.
Bug Fix: Layer effects applied to smart objects are now preserved in the rendered image.
Enhancement: Improved compositing of overlay layer effects to more closely match Photoshop.

Bug Fix: CorelDRAW files now render their content instead of appearing black or blank. (.NET 4.7 build only)
Bug Fix: WebP images that previously failed to process now open and convert correctly. (.NET 4.7 build only)
Enhancement: BMP files with a malformed header are now corrected on load instead of being rejected. (.NET 8, .NET 6 V2 and .NET Standard 2.1 V2 builds)

Bug Fix: Binary files are no longer misidentified as MHTML documents, so they fail with a clear error instead of opening as an empty message.