We’re happy to announce the GroupDocs.Merger for .NET 25.11 release, available as of November 2025. This update brings a new capability for tagged‑PDF merging, a set of cross‑platform bug fixes, and several quality improvements.

What’s new in this release

New feature

  • Preserve accessibility metadata when merging tagged PDFs – a new PreserveAccessibility option in the PdfJoinOptions class lets you keep the PDF/UA structure (tags) of source documents during a merge. When enabled, the resulting PDF contains auto‑generated accessibility tags, improving compliance with assistive‑technology requirements.

Enhancement

  • Improved handling of accessibility metadata – the underlying merger logic has been updated to retain the tagged‑PDF information rather than discarding it, which reduces the need for post‑merge accessibility remediation.

Using the new API

using GroupDocs.Merger;
using GroupDocs.Merger.Options;

// ...

var pdfJoinOptions = new PdfJoinOptions
{
    PreserveAccessibility = true   // keep PDF/UA tags
};

merger.Join(sourceFiles, pdfJoinOptions);

Fixes and enhancements

Category Issue ID Summary
Bug MERGERNET-2050 Diagram document operations fail on macOS/Linux because of missing font paths.
Bug MERGERNET-1007 Merging several Word files can create duplicate pages.
Bug MERGERNET-1102 Exception “Rounding digits must be between 0 and 15, inclusive” when merging two DOCX files.
Bug MERGERNET-987 Merged document size grows excessively.
Bug MERGERNET-1174 Unable to change PDF page orientation during merge.
Bug MERGERNET-2049 VSD format operations throw NullReferenceException.
Bug MERGERNET-2070 Corrupted output when the new merged PDF is shorter than the existing file.
Bug MERGERNET-2053 Merging PDF and SVG fails on macOS due to missing font configuration.
Bug MERGERNET-2051 Note document operations fail on macOS/Linux because of missing font paths.
Bug MERGERNET-799 SetVentureLicensed method in Slides venture licensing does not work correctly.

Additional improvements

  • The merger engine now performs more robust validation of input streams, which reduces the likelihood of unexpected NullReferenceExceptions on edge‑case files.
  • Internal performance tweaks decrease the CPU load for large‑scale PDF joins when PreserveAccessibility is disabled.

How to get the update

  • NuGet – Upgrade to the latest GroupDocs.Merger package (v 25.11) via the NuGet Gallery:
    dotnet add package GroupDocs.Merger --version 25.11.0
    or use the Package Manager Console:
    Install-Package GroupDocs.Merger -Version 25.11.0

  • Direct download – Assemblies for .NET 6/.NET Framework are available on the GroupDocs release page (if you need a zip bundle, check the Downloads section of the release notes).

Resources

If you have any questions or run into issues, feel free to drop a note in the forum or open a support ticket. Happy merging!