dotnet/Open-XML-SDK

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Open XML SDK by Microsoft

Stars: 4.6k
Forks: 605
Open beginner issues: 0
Indexed issues: 96

Dominant language: C#
License: MIT
Last GitHub push: Aug 18, 2026
Latest indexed: Sep 15, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted
PR merge metrics: No merged PRs in 30d

Open All

96 open issues indexed

System.IO.IOException: Stream was too long error on .NET Core 2.0 application Open

blocked: corefx System.IO.Packaging bug no-issue-activity

dotnet/Open-XML-SDK#244 · 17 comments · 13 reactions · 0 assignees · Indexed Sep 15, 2026
Element classes do not contain all child element-related properties Open

enhancement schema

dotnet/Open-XML-SDK#492 · 18 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
DOCX Validation reporting 0 errors on invalid document Open

no-issue-activity schema

dotnet/Open-XML-SDK#592 · 9 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
ChangeDocumentType does not fully remove vbaProject reference Open

dotnet/Open-XML-SDK#618 · 7 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
CellReference is null Open

bug

dotnet/Open-XML-SDK#672 · 15 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Cannot open presentation theme (.thmx) file Open

request: feature

dotnet/Open-XML-SDK#739 · 5 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
AOT in Xamarin results in very large DLL in v2.11.1+ Open

architecture high impact

dotnet/Open-XML-SDK#753 · 3 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
Instrument project with DiagnosticSource Open

help wanted up for grabs

dotnet/Open-XML-SDK#762 · 2 comments · 1 reaction · 1 assignee · Indexed Sep 15, 2026
Misc element properties are not lining up with their ECMA definitions Open

request: feature

dotnet/Open-XML-SDK#780 · 14 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
The UpRight property in DocumentFormat.OpenXml.Drawing.BodyProperties may be named incorrectly Open

dotnet/Open-XML-SDK#784 · 1 comment · 1 reaction · 1 assignee · Indexed Sep 15, 2026
This document is missing a relationship Open

enhancement

dotnet/Open-XML-SDK#863 · 7 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
AddAlternativeFormatImportPart produces malformed documents if both parent and child contain shape-lines or similar objects Open

request: feature

dotnet/Open-XML-SDK#917 · 6 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Cannot apply styleindex in Excel using OpenXml SDK Open

more-information-needed

dotnet/Open-XML-SDK#926 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Image not shown correctly after removing some other images from Table via removal of Rows Open

dotnet/Open-XML-SDK#935 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
w:sdtContent-related classes should inherit from SdtContentElement or similar Open

api-design-needed help wanted request: feature

dotnet/Open-XML-SDK#944 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Strongly typed classes define all properties as nullable Open

by design enhancement has-repro

dotnet/Open-XML-SDK#960 · 7 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
New DOCX document is created with Override node rather than Default node in [Content_Types].xml Open

more-information-needed

dotnet/Open-XML-SDK#994 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Openxml - Export to Excel rendering html tag not working Open

dotnet/Open-XML-SDK#1003 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
OpenXmlSimpleType values should not allow null Open

no-issue-activity

dotnet/Open-XML-SDK#1009 · 0 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
Can `LoadFromPart` set `OpenXmlPart` instead? Open

dotnet/Open-XML-SDK#1010 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
OpenXmlPartRootElement should raise the IPartRootEventsFeature.Changed on reload Open

dotnet/Open-XML-SDK#1023 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`TextMath` object drops child elements when clone Open

bug

dotnet/Open-XML-SDK#1033 · 4 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Set the font for a text run is not working Open

more-information-needed needs-repro

dotnet/Open-XML-SDK#1039 · 7 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Adding image to document with image in header: Existing image no longer visible Open

dotnet/Open-XML-SDK#1040 · 12 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Static cache takes up too much memory Open

dotnet/Open-XML-SDK#1062 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Why office365 xlsx sheet utf8 encoding but openxmlsdk is utf8-withbom Open

dotnet/Open-XML-SDK#1064 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
PresentationDocument.Save() performance weirdness Open

performance

dotnet/Open-XML-SDK#1079 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
The second attempt to open an unchanged presentation file for edit throws a "file contains corrupted data" error. Open

more-information-needed

dotnet/Open-XML-SDK#1135 · 6 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`PresentationDocument.Save()` doesn't apply changes Open

dotnet/Open-XML-SDK#1147 · 7 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
external table is not in expected format Open

more-information-needed needs-repro

dotnet/Open-XML-SDK#1183 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
ChangeDocumentType (.xlsm) to (.xlsx) not removing /xl/vbaProject.bin Open

bug more-information-needed no-issue-activity

dotnet/Open-XML-SDK#1209 · 13 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
CustomUI having wrong namespace Open

bug

dotnet/Open-XML-SDK#1210 · 8 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
OpenXmlValidator.Validate() returns error for valid presentation Open

bug

dotnet/Open-XML-SDK#1218 · 11 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Open XML Productivity Tool should normally open files read-only Open

enhancement

dotnet/Open-XML-SDK#1221 · 2 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Bug with Open XML SDK: PowerPoint could not open the file created by v2.18 with mc:AlternateContent element Open

bug no-issue-activity

dotnet/Open-XML-SDK#1226 · 20 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
FlatOpc: line break at the end of binary part format Open

enhancement

dotnet/Open-XML-SDK#1237 · 3 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
I use AddAlternativeFormatImportPart attach document thet contains list numbering,the list numbering is malformed in office 365, and fine in office 2019.Bug with Open XML SDK Open

more-information-needed

dotnet/Open-XML-SDK#1262 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Review generated namespace hierarchy Open

breaking-change

dotnet/Open-XML-SDK#1278 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Consider supporting alternate content blocks at root of part content Open

enhancement

dotnet/Open-XML-SDK#1291 · 8 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Split assembly in separate packages for DOCX / XLSX / PPTX Open

high impact

dotnet/Open-XML-SDK#1313 · 11 comments · 1 reaction · 1 assignee · Indexed Sep 15, 2026
Macro-enabled document created with CreateFromTemplate() cannot be opened by Word Open

dotnet/Open-XML-SDK#1314 · 3 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Bug with Open XML SDK Open

more-information-needed

dotnet/Open-XML-SDK#1338 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Enable better AOT support for SDK Open

architecture

dotnet/Open-XML-SDK#1348 · 0 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
Ensure a package only references required types Open

architecture

dotnet/Open-XML-SDK#1349 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Open document fail when Content_Types records paths with wrong case Open

blocked: corefx System.IO.Packaging

dotnet/Open-XML-SDK#1355 · 3 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
Comments for LINQ generated code does not contain inherited attributes/elements Open

architecture

dotnet/Open-XML-SDK#1356 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Investigate ITargetFeature use to redirect target path for EmbeddedPackage and EmbeddedObject (and other) parts. Open

dotnet/Open-XML-SDK#1406 · 1 comment · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Validation of CalcChain considers s attribute of a cell to be a style index Open

dotnet/Open-XML-SDK#1411 · 2 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Method not found w/ System.IO.Packaging version 7.0.0 Open

more-information-needed

dotnet/Open-XML-SDK#1428 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Open XML SDK ZIP local file header is not compliant to ISO/IEC 29500-2. Incorrect "general purpose bit flag" settings Open

external

dotnet/Open-XML-SDK#1443 · 21 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026

dotnet/Open-XML-SDK

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