Issues

• ObjectSizeTests.cs uses #if NET462 || NET but NET462 is not defined

  dotnet/Open-XML-SDK#2147 · Filter by author jafin opened on Sep 19, 2026
  1

• Provide a way to describe the root element of a VML part

  dotnet/Open-XML-SDK#2145 · Filter by author m-gallesio opened on Sep 18, 2026

• OpenXmlValidator rejects a valid CT_Filters holding both filter and dateGroupItem

  dotnet/Open-XML-SDK#2128 · Filter by author jafin opened on Aug 1, 2026

• New project: OOXML Behavioral Intelligence — behavioral spec research

  dotnet/Open-XML-SDK#2119 · Filter by author nessim-liamani opened on Jul 21, 2026
  1

• Documentation Request - Document impossibility to pass in a write-only, non-seekable stream when generating a document

  dotnet/Open-XML-SDK#2113 · Filter by author Fube opened on Jul 7, 2026
  1

• Improve loading performance of Populate

  dotnet/Open-XML-SDK#2095 · Filter by author jscarle opened on Jun 10, 2026
  1

• WordprocessingDocument.Open returns null MainDocumentPart when [Content_Types].xml omits Default Extension="rels"

  dotnet/Open-XML-SDK#2091 · Filter by author rakeshbabuseva opened on Jun 2, 2026
  

• MarkupCompatibilityProcessSettings corrupt document for ligatures set in document text

  dotnet/Open-XML-SDK#2086 · Filter by author fsberuk opened on May 15, 2026

• BUG: OpenXml 3.x: SpreadsheetDocument.Open(Stream, false) requires temp/write access (breaks read-only environments)

  dotnet/Open-XML-SDK#2081 · Filter by author NkhilKajrekar opened on May 11, 2026
  12

• Use a pooled StringBuilder for all instances of it

  dotnet/Open-XML-SDK#2073 · Filter by author twsouthwick opened on Apr 28, 2026
  

• Feature request for Open XML SDK

  schema
  dotnet/Open-XML-SDK#2048 · Filter by author alomakin-msft opened on Mar 26, 2026
  3

• API Proposal: Formula Evaluation Feature

  dotnet/Open-XML-SDK#1973 · Filter by author mliotta opened on Nov 13, 2025
  4

• Use specialized URI type for package spec that is more relaxed than System.Uri

  dotnet/Open-XML-SDK#1965 · Filter by author twsouthwick opened on Sep 29, 2025
  1

• Malformed URIs are not rewritten

  dotnet/Open-XML-SDK#1962 · Filter by author larrygfr opened on Sep 11, 2025
  1

  

• commentParts should have a capitol C

  breaking-changebug
  Bug

  dotnet/Open-XML-SDK#1958 · Filter by author mikeebowen opened on Aug 8, 2025 · v4.0

• Bug Report: System.OutOfMemoryException when writing large Excel file

  bug
  dotnet/Open-XML-SDK#1951 · Filter by author sw-ms-hardiksenghani opened on Jul 1, 2025
  3

  

• Remove PivotCacheDynamicArray class

  breaking-change
  dotnet/Open-XML-SDK#1945 · Filter by author mikeebowen opened on Jun 24, 2025 · v4.0

• Add Feature Extension and List for CT_CustomSheetView and CT_SheetView

  breaking-change
  dotnet/Open-XML-SDK#1943 · Filter by author mikeebowen opened on Jun 24, 2025 · v4.0

• Bug with Open XML SDK Disposing SpreadsheetDocument

  needs-repro
  dotnet/Open-XML-SDK#1942 · Filter by author JoseAngelSalmeronMorote opened on Jun 24, 2025
  3

  

• The DocumentFormat.OpenXml.Office2010.Drawing.TextMath should not inherit OpenXmlLeafElement

  breaking-changebug
  dotnet/Open-XML-SDK#1940 · Filter by author lindexi opened on Jun 20, 2025 · v4.0
  2

  

• Remove DocumentFormat.OpenXml.Office.SpreadSheetML.Y2024.PivotDynamicArrays namespace

  breaking-changeschema
  dotnet/Open-XML-SDK#1939 · Filter by author mikeebowen opened on Jun 18, 2025 · v4.0

• Add Async XmlReader methods

  enhancement
  dotnet/Open-XML-SDK#1903 · Filter by author mikeebowen opened on Mar 19, 2025 · v4.0
  

• Remove pTasksDeprecated.xsd

  breaking-change
  dotnet/Open-XML-SDK#1885 · Filter by author mikeebowen opened on Mar 3, 2025 · v4.0

• ChartExtension and ChartExtensionList are not implemented

  breaking-changebug
  Bug

  dotnet/Open-XML-SDK#1877 · Filter by author mikeebowen opened on Feb 26, 2025 · v4.0

• authorsPart should have a capital A.

  breaking-change
  Bug

  dotnet/Open-XML-SDK#1855 · Filter by author mikeebowen opened on Dec 30, 2024 · v4.0