WinUI 3 in Windows App SDK 2.6.5 picks up runtime hotfixes for rendering, window composition, system backdrops, and packaged app installation. It is available through the Microsoft.WindowsAppSDK 2.6.5 NuGet package.

Bug fixes

• Fixed rendering corruption on systems with multiple graphics adapters or monitors, plus unexpected transparency in window backgrounds and GDI controls on Windows 10, including apps hosting XAML islands.
• Fixed an E_NOINTERFACE crash when enabling the System Composition Engine on Windows builds without the required interfaces. The runtime now uses the lifted compositor on those builds.
• Reverted the system backdrop change introduced in 2.6.4 to address wrong-thread exceptions. System backdrops for content islands and XAML windows are not supported when using the System Composition Engine in this release.
• Fixed an issue where app-extension registration metadata generation returned E_NOTIMPL, which could prevent packaged apps from installing.

For the full set of changes, see the Windows App SDK 2.6.5 release notes.

Try it out

• Install the Microsoft.WindowsAppSDK 2.6.5 NuGet package.