[release-notes] .NET 11 Preview 6 by danroth27 · Pull Request #10455 · dotnet/core

danroth27 · 2026-06-29T19:02:22Z

.NET 11 Preview 6 release notes

Draft release notes for .NET 11 Preview 6 (runtime 11.0.0-preview.6.26328.106, SDK 11.0.100-preview.6.26328.106).

This base PR holds the shared milestone metadata. Each component's notes live in a separate PR targeting this branch (release-notes/11.0-preview6) so the owning team can review its file in isolation. As the component PRs merge here, this PR's diff becomes the full milestone.

Contents of this PR

README.md — milestone index
changes.json — 2,320 shipped changes from the VMR source-manifest.json diff
features.json — schema stub (per-component feature selection lives in each component PR)
build-metadata.json — build + NuGet feed used for API verification

VMR refs

Base: v11.0.0-preview.5.26302.115
Head: release/11.0.1xx-preview6

Notes

All component PRs are opened as drafts for team review.
The milestone landing page (11.0.0-preview.6.md) is intentionally not included; it is produced by the release team's publishing automation.

🤖 Generated with the release-notes skill.

changes.json, features.json, build-metadata.json, and README for the .NET 11 Preview 6 milestone (VMR base v11.0.0-preview.5.26302.115 -> head release/11.0.1xx-preview6). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* [release-notes] C# in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Update release-notes/11.0/preview/preview6/csharp.md --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Bill Wagner <wiwagn@microsoft.com>

* [release-notes] MSBuild in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Add bug-fix note for architecture-agnostic Runtime=NET task host handshake (dotnet/msbuild#13890) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * Remove HTML comments from Preview 6 MSBuild release notes Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Chet Husk <chusk3@gmail.com>

* [release-notes] NuGet in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix STJ feature-flag env var value and remove VS reference Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Chet Husk <chusk3@gmail.com>

* [release-notes] .NET SDK in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Clarify NativeAOT CLI updates in preview6/sdk.md Updated the NativeAOT CLI section to clarify the unification of managed and NativeAOT parsers, and removed filtered content related to internal changes. * Add live running-tests display to dotnet test notes Document the in-flight test progress panel (dotnet/sdk#54486) and fix pre-existing trailing-space lint errors in the NativeAOT section. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Chet Husk <baronfel@users.noreply.github.com> Co-authored-by: Chet Husk <chusk3@gmail.com>

* [release-notes] Windows Forms in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Revise Windows Forms release notes for Preview 6 Updated release notes for .NET 11 Preview 6 to include bug fixes and improvements for various Windows Forms components. --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Klaus Löffelmann <9663150+KlausLoeffelmann@users.noreply.github.com>

* [release-notes] .NET MAUI in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Draft .NET MAUI and friends notes for .NET 11 Preview 6 Combined highlights for .NET MAUI, .NET for Android, and .NET for iOS, Mac Catalyst, macOS, and tvOS: CollectionView2 on Windows, handler-based Shell on Android, Compatibility package removal, AOT-safe HybridWebView, Geolocation minimum-distance filter, a reliability wave, the AndroidMessageHandler HTTP-contract work, and the Apple platform toolchain and NSUrlSessionHandler updates. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * Add Preview 6 items from MAUI maintainer review Incorporates jfversluis review feedback on #10467: - Android MediaPicker result recovery APIs (dotnet/maui#35455) - HybridWebView Android message-source filtering (dotnet/maui#35717) - XAML C# expression source generator CS1061 fix (dotnet/maui#35922) - Testable permissions via IPermissions/Permissions.Current (dotnet/maui#35987) - XA0149 warning for legacy __AndroidEnvironment__ resources (dotnet/android#11700) - Skip library proguard.txt with disallowed R8 global options (dotnet/android#11709) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: David Ortinau <david.ortinau@microsoft.com>

Co-authored-by: AndriySvyryd <6539701+AndriySvyryd@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* [release-notes] Containers in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Update release notes --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Logan Bussell <loganbussell@microsoft.com>

* [release-notes] .NET Libraries in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix async DataAnnotations sample after testing on the Preview 6 SDK AsyncValidationAttribute is overridden via the protected IsValidAsync (and IsValid) members, not GetValidationResultAsync (which is the public method the framework calls and is not virtual). Verified the corrected sample compiles and runs against the Preview 6 build. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Verify Preview 6 library samples and fix inaccuracies - Stream adapters: read from the read-only stream via StreamContent/PostAsync instead of copying HttpContent into it - Cross-lane vectors: replace nonexistent Concat with ConcatLowerLower/LowerUpper/UpperLower/UpperUpper and drop preexisting Shuffle/ShuffleNative - Async validation: swap the unique-username example for a VAT registry lookup, layer StringLength and RegularExpression sync rules with the async rule, and add a server-side validation note Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Jeff Handley <jeffhandley@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

azure-pipelines · 2026-07-14T05:01:58Z

Azure Pipelines: There may be pipelines that require an authorized user to comment /azp run to run.

danroth27 · 2026-07-14T05:03:43Z

@davpetr

Copilot

Pull request overview

Adds the initial set of per-component markdown release notes and milestone metadata for .NET 11 Preview 6 under release-notes/11.0/preview/preview6/, aligning content with the preview’s builds/refs and component ownership model described in the PR.

Changes:

Introduces Preview 6 component release-note drafts (libraries, SDK, ASP.NET Core, EF Core, MAUI, MSBuild, NuGet, languages, Windows Desktop).
Adds milestone metadata stubs (features.json, build-metadata.json) and the Preview 6 landing README.md.
Includes “no notable changes” notes for components without new user-facing features (for example, WPF).

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
release-notes/11.0/preview/preview6/README.md	Adds Preview 6 milestone index, versions, and VMR refs.
release-notes/11.0/preview/preview6/build-metadata.json	Records build + NuGet feed inputs for verification.
release-notes/11.0/preview/preview6/features.json	Provides the per-milestone features schema stub.
release-notes/11.0/preview/preview6/libraries.md	Drafts Preview 6 libraries highlights and breaking changes.
release-notes/11.0/preview/preview6/sdk.md	Drafts Preview 6 SDK/CLI/testing highlights and bug fixes.
release-notes/11.0/preview/preview6/aspnetcore.md	Drafts Preview 6 ASP.NET Core features, samples, and preview API changes.
release-notes/11.0/preview/preview6/efcore.md	Drafts Preview 6 EF Core feature and fix coverage.
release-notes/11.0/preview/preview6/dotnetmaui.md	Drafts Preview 6 MAUI/platform updates and contributor list.
release-notes/11.0/preview/preview6/msbuild.md	Drafts Preview 6 MSBuild features, perf notes, and fixes.
release-notes/11.0/preview/preview6/nuget.md	Drafts Preview 6 NuGet client changes and breaking changes.
release-notes/11.0/preview/preview6/csharp.md	Drafts Preview 6 C# language/compiler updates.
release-notes/11.0/preview/preview6/fsharp.md	Drafts Preview 6 F# language/compiler updates and fixes.
release-notes/11.0/preview/preview6/containers.md	Drafts Preview 6 container image update highlights.
release-notes/11.0/preview/preview6/winforms.md	Drafts Preview 6 WinForms bug-fix list.
release-notes/11.0/preview/preview6/wpf.md	Adds WPF note indicating no new user-facing changes.

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

BillWagner

Approved for C# as of commit 15.

@DeagleGross

- OpenAPI unions: correct the third-party generator claim (ApiExplorer does not detect unions via JsonTypeInfoKind.Union; Swashbuckle/NSwag don't yet recognize unions). Per @DeagleGross review on #10456. - Blazor Virtualize: note that a user scroll during ScrollToIndexAsync wins. Per @ilonatommy review on #10456. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- CSRF: note that Blazor Web App templates no longer call app.UseAntiforgery(). - Bug fixes/Blazor: Virtualize is now CSP-compliant (#66680); session cookie is issued before streaming SSR for [SupplyParameterFromSession]/TempData (#66832). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

DeagleGross

approved for Unions & CSRF

…eature WithBrowserOptions flows client-side Blazor.start configuration from the server in C# (log level, Server reconnection, SSR DOM preservation, WASM environment), serialized to the client across Server/WebAssembly/Auto render modes. Introduced in Preview 4 (server-to-browser config via DOM comment) and reshaped in Preview 6 (dotnet/aspnetcore#67337, proposal #66393). Includes the reshape/rename migration for earlier adopters. Sample build-verified on 11.0.100-preview.6.26359.118. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

danroth27 · 2026-07-14T15:34:49Z

@guardrex

ilonatommy

Virtualize approved.

@ilonatommy

Reviewing dotnet/AspNetCore.Docs#37322 surfaced that the attribute is data-blazor-virtualize-reserved-height (only the server-computed spacer height), not the generic data-blazor-style. Verified in the P6 source (Virtualize.cs / Virtualize.ts). @ilonatommy corrected the same wording on the docs PR. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* [release-notes] .NET Runtime in .NET 11 Preview 6 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Enrich Preview 6 runtime notes with additional verified features Fold verified .NET 11 Preview 6 runtime changes into runtime.md (JIT improvements, in-process crash logging, NativeAOT interface dispatch, SIMD lane APIs, and an expanded bug-fix list), and rebuild the TOC to match the current sections. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: ade796bb-8052-4946-b204-a88518267e77 --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: Rich Lander <2608468+richlander@users.noreply.github.com>

Co-authored-by: jongalloway <68539+jongalloway@users.noreply.github.com>

[release-notes] .NET 11 Preview 6 base metadata
8dc890d
changes.json, features.json, build-metadata.json, and README for the .NET 11 Preview 6 milestone (VMR base v11.0.0-preview.5.26302.115 -> head release/11.0.1xx-preview6). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

danroth27and others added 12 commits July 10, 2026 14:09

[release-notes] EF Core in .NET 11 Preview 6 (#10462)
0ec4229
Co-authored-by: AndriySvyryd <6539701+AndriySvyryd@users.noreply.github.com>

[release-notes] F# in .NET 11 Preview 6 (#10461)
bd98d33
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

[release-notes] ASP.NET Core in .NET 11 Preview 6 (#10456)
84b5a49

[release-notes] WPF in .NET 11 Preview 6 (#10466)
2146c4b
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

danroth27 marked this pull request as ready for review July 14, 2026 05:01

danroth27 requested review from leecow and rbhanda as code owners July 14, 2026 05:01

danroth27 requested a review from Copilot July 14, 2026 05:03

Copilotstarted reviewing on behalf of danroth27 July 14, 2026 05:04 View session

CopilotAI reviewed Jul 14, 2026
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danroth27and others added 2 commits July 13, 2026 22:13

Apply suggestions from code review
82678f9
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Throw InvalidOperationException for sync validation of async validator
4aab808
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

BillWagner approved these changes Jul 14, 2026
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danroth27 requested review from DeagleGross, Youssef1313 and ilonatommy July 14, 2026 14:21

DeagleGross approved these changes Jul 14, 2026
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danroth27 mentioned this pull request Jul 14, 2026
[11.0 P6] Blazor Preview 6 coverage dotnet/AspNetCore.Docs#37322
Merged

ilonatommy approved these changes Jul 14, 2026
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danroth27and others added 2 commits July 14, 2026 08:47

rbhanda approved these changes Jul 14, 2026
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Merge branch 'main' into release-notes/11.0-preview6
9532f89

Copilotstarted work on behalf of jongalloway July 14, 2026 17:53 View session

fix markdown lint in preview6 containers note
38fe4b3
Co-authored-by: jongalloway <68539+jongalloway@users.noreply.github.com>

Copilotfinished work on behalf of jongalloway July 14, 2026 17:57

CopilotAI requested a review from jongalloway July 14, 2026 17:57

jongalloway approved these changes Jul 14, 2026
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rbhanda approved these changes Jul 14, 2026
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rbhanda merged commit 4f4892f into mainJul 14, 2026
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rbhanda deleted the release-notes/11.0-preview6 branch July 14, 2026 18:01

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[release-notes] .NET 11 Preview 6 - #10455

[release-notes] .NET 11 Preview 6#10455
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danroth27 commented Jun 29, 2026

.NET 11 Preview 6 release notes

Contents of this PR

VMR refs

Notes

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