Cannot create a new WinUI 3 app and target .NET 8 about microsoft-ui-xaml HOT 5 CLOSED

That error is curious, it is also an error I do not see. Anyway, to go through the important points.

1. The projects being out of date is a known issue. The updated project templates that have .NET 8 support can be found here. You cannot build the .vsix file, but there is nothing stopping you from using these files to properly configure a new project. As an example to show this, there is a response to another bug report last month stating that the new project templates are on the way.

2. If you are using the Windows App SDK 1.5, you really shouldn't need UseRidGraph. A project that I created to test this out works perfectly fine with:

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net8.0-windows10.0.19041.0</TargetFramework>
    <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
    <RootNamespace>CsTest</RootNamespace>
    <ApplicationManifest>app.manifest</ApplicationManifest>
    <Platforms>x86;x64;ARM64</Platforms>
    <RuntimeIdentifiers>win-x86;win-x64;win-arm64</RuntimeIdentifiers>
    <PublishProfile>win-$(Platform).pubxml</PublishProfile>
    <UseWinUI>true</UseWinUI>
    <EnableMsixTooling>true</EnableMsixTooling>
    <Nullable>enable</Nullable>
  </PropertyGroup>

If you want this to work with all frameworks, then using the method in the project templates will work.

3. The crash at XamlCheckProcessRequirements basically mean that you do not have the Windows App Runtime referenced. If your application is packaged, then you really need to provide a sample project that exhibits this behaviour since the build system should be picking up the reference from the NuGet package. If your application is unpackaged then you missed a step in the "Create your first WinUI 3 (Windows App SDK) project" link that you provided.
   As per step 7 in the unpackaged section, you need to set WindowsPackageType to none in the .csproj file. This will bootstrap the Windows App Runtime into the process and allow Xaml to work.
   There is an added annoyance here in that using WindowsPackageType set to none will break the packaging for this type of project. There are ways around it if you want the application to work seamlessly packaged or unpackaged.

from microsoft-ui-xaml.

After rebooting the development machine (ad hoc, just to see if it would help), the project builds and runs on .NET 8 without issues. As others on the GitHub thread have indicated it is not replicable in their existing environments, it seems to me that maybe the documentation should say a restart is required, or the SDK installer should prompt for a reboot?

from microsoft-ui-xaml.

Glad to hear you're unblocked! If you come across more detail on what configuration change required a reboot, please let us know. thanks!

from microsoft-ui-xaml.

It was a fresh installation of WinUI 3 SDK onto a Window 11 development machine with an existing Visual Studio 2022 environment.

from microsoft-ui-xaml.

Hi again, if anyone else hits this, you might also try uninstalling the WinAppSDK template extension from Visual Studio and then re-installing the latest. If you installed the standalone version from a past download link, it won't be updated in-place.

Thanks!

from microsoft-ui-xaml.