Windows App SDK 1.8.8 (1.8.260508005)

[agniuks]

WinAppSDK 1.8.8 is the latest stable servicing release for 1.8, focused on reliability and developer-experience fixes across XAML, package management, Windows AI, and the build-time NuGet tooling.

Bug fixes:

Bug Fix	Runtime Compatibility Change
Fixed an issue where windowed popup content opened in a XAML Island did not respect OverrideScale, causing content to appear oversized and clipped (microsoft/microsoft-ui-xaml#11000).	Popup_WindowedPopupOverrideScale
Fixed an ACCESS_VIOLATION crash in RenderTargetBitmap.RenderAsync that occurred when the target element left the visual tree (for example, a popup closing) before the capture completed.	RTB_CancelRenderOnTreeLeave
Fixed a potential crash in package management when a package was uninstalled prior to being processed.	PackageManager_FixCrash
Fixed an issue where GetReadyState could return incorrect error codes when required Windows AI packages were not yet deployed. The API now correctly reports NotReady, improving diagnostic clarity and reducing false-positive failure signals in telemetry.	ModelInitialization_GetReadyStateAvailabilityGuard
Improved internal performance diagnostics for LanguageModel.GenerateResponseAsync to better identify sources of latency before the first token is returned.	LanguageModelInsights_GetPartialResultLatency
Fixed a fail-fast crash caused by re-entrant dispatch during cross-apartment COM release operations in UIAffinityReleaseQueue::DoCleanup.	UIAffinityReleaseQueue_PauseDispatchDuringCleanup
Fixed an issue where Microsoft.Windows.Workloads.dll failed to load on Windows builds prior to 22000 due to static imports of Dynamic Dependencies APIs unavailable on those OS versions. The functions are now resolved dynamically; failures on unsupported OS versions surface as a normal HRESULT instead of a loader error dialog.	PackageDependency_ResolveDynamically
Fixed an issue where XAML compiler errors were silently lost when using dotnet build, showing only MSB3073: exited with code 1 instead of the actual error messages (microsoft/microsoft-ui-xaml#9813).	N/A (build-time tooling change)
Fixed a design issue in the WinAppSDK NuGet .targets files where %(PreprocessorDefinitions) references inside MSBuild <Target> blocks triggered task batching, causing the same auto-initializer source file to be added to ClCompile multiple times and producing duplicate .obj outputs (MSB8027 / LNK4042 warnings). Definitions are now set via <ItemDefinitionGroup>. An opt-out property (WindowsAppSDK_Arm64EcCompilerWorkaround) is included for ARM64EC+LTCG builds (microsoft/WindowsAppSDK#5395).	N/A (build .targets change)

To see everything that's new and changed, see the full Windows App SDK 1.8.8 release notes.

Try it out

• Download the 1.8.260508005 NuGet package to use WinAppSDK 1.8 in your app.

Getting started

To get started using Windows App SDK to develop Windows apps, check out the following documentation:

• Install developer tools.
• Create a WinUI 3 app.
• Continue your development journey.

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This discussion was created from the release Windows App SDK 1.8.8 (1.8.260508005).